That you would rather do. I know. I think those topics are great. My. Modeling. Or maybe could I do some a level topics or what a level topics are there? Yeah, of course. I don't see anything that's on your mind. No, I don't know. Like I well, is there any a level topics that I can learn right now? Yeah, of course. Let me let me have a look. What course are you doing again? Cie. I think cie I don't know any a level is okay. I think it's okay. Let me have a look. Syllabus. Okay, so let's do some interesting stuff. Data representation. Oh, no, that's boring for you. You know this already. Okay. All right, we can do some things from chapter two in networks. I'm not sure if that would interest you. So so networks. Internet, okay. So what do you remember about the Internet? It's just a network that connects different computers. Yep. And how do they communicate? Through lthrough lwhat else. What does land stand for? Local area network? Yes. And how do they communicate area? Yeah wide area network. What's a wide area network? Just labut across the figure area. Yeah, exactly. Great. And what how do they communicate? Ip partoals. So they've got ip what does ip stand for? Internet protocol Yeah what's inside of an of an what is ip really? Well, how does it work? Internet. There are rules about your local address, your public address and how to send and receive data. Address receive, slash send, and how does it send data? You know? So where does it put the address, the receive, the send, things like this? Gives the targeted ip to it can it depends. I think it depends if they're just in one land or in or across different networks. Yeah, that's but how does it send this p? How does it concretely work? I'm looking for something else, something more basic. Maybe we haven't mentioned yet. Sends the data to the targeted address and. In packets. Yes, packets. There you go. Packets. That's what I was looking for. And what does an ip packet look like? You said most of it already, but I just want to solidify a bit of what you're saying. And maybe you remember the structure of an ip packet. There's there's definitely the address. Yep, the address. What else do you remember? We didn't cover much of it. But if the data Yep, that's going to be this big block data, what else? There's either a correction algorithm or a. I forgot the other one. Yeah you're called red sir. The one that it has to send back. That's something else. So that's something else so this by I'll go. I mean, for example, if the if the bits bits are corrupted ithave like a checksum. I don't know. Do you know what checksuis? Yeah, right. So for example, algo will usually be and then itusually be like a 16 bit sequence of which algorithm it's usually using to make sure that bit the packet is not damaged, but that that's different what we're talking about, right? We'll get back to that in a second. What else do you remember address algorithm? No, I think that's all I remember. Yeah, okay, that's address. That's a receiver address. And then there's the sent address, which I guess is not super, super important, but there's that and there's a few other parameters which I won't get into. So that's an ip packets and you've got multiple of them, right? So you're going to have lots and lots when you send over some data. So what you were talking about before was interesting. What's inside this data block? There's always going to be something else inside this data block. And what you would is metadata. Yeah. So you got metadata. What else is there? What is metadata, by the way? Extra information. Extra info. Yeah. I like to say information about information. Yeah, what else is there inside of the data section? The actual data, the data. And how 's that package? You were onto something when you were talking before. I said we covered it later. Yes. Udp slash tcp. What's the difference between the two? One is send and forget. One is send and receive a confirmation package. Which one is the send them receipt? Tcp, yes. So yes, exactly. So we call these acts. And the way we structure it is you've got your ip packet like this. So this is your acknowledgement. Yeah, acknowledgement. Yeah, that's it. So you've got your ip packet here. And inside of the ip packet, as we saw, like it had all its data here. So it's got the address, right? The algo, and it has this data here. And inside the data section, you have a udp slash tcp packet. It's udp slash tcp, and then it's got its own sets, right? So what might we find inside of a tcp packet? Some sort of well label that some sort of key or label that I sometimes thanks for the specific packing exactly Slaid. And this is usually just a number. So like zero one, zero two, great. And that it's used to a sequence is a sequence number c sec ID ID sec brait and it has its own algo usually as well. So an algorithm. And inside of here, finally, we just have bytes. So actually in real life, you've only got like 65 ish. Approximately 65% of an ip packet is data. The rest is just data about data. It's meta data, right? It's the ip is the address. Great. Okay, that's nice. How about how about security? Okay, so let's before we get onto that, how does it routes from computer a to computer b, right? Let's say it has a network here like this, right? How does it find the path? What is the, you know, how does it work? It gives it to its modern, and then the Roter, it gives it to its Roter, and the Roter can root two. Well, another router which rouots to another, leading to be, they have the PaaS updated inside of them. Yes, exactly. So so it's a big path list basically. And they update each other frequently. So theysend updates to each other like this, this guy will send a message maybe to this guy and hesay, Hey, I've got new data and then the guy will say, okay, great. And then he's gonna update his routing table with all of this guy's routing table. So you may end up with a big table of where to go for each p addresses because there's not that many ip addresses, about 4 billion of them, which when you think about it is pretty you know it's is small in hunt actually and we're actually running out of them which is why we have ipv six. You know what ipv six is 128 bid system. Yeah this is a big boy. This one we're not gonna to run out of yet. Okay, great. So that's how that works. Have we covered security tls? I think a bit, but not much tls. So what does tls stands for? Do you know maybe no transport. Yer Transport Layer Security. And what that is really is just it's basically a security layer. Now you have a bunch of different ways we can do security. Have you heard of public and private? Yeah. What is it? It's a. But which type of encryption algorithm are we talking about that? Okay. So you know what? Well, say you're using. Well, I can't even think of one by head, but Shaha, 256, well, that's not going to work. But basically the idea of private versus public, right? So do you understand the idea of private versus public? Okay. So would you mind explaining to me very quickly so I can just write it down and move on? They both have a private key each, and they mix the private key with another random number and send it by a public key. Mixed by. And then send unlog and then. And the specific algorithm, just after a few exchanges, can figure and then mixes it with their other private key and then. Because one party knows both the his private key and the number he mixed it with, he can deduce that private key. Yeah exactly. Very nice. I mean you you seem to understand well this this method but basically Yeah if you have if you encrypt with this private ski, you can decrypt with this. So if you this would be for broadcasting, right? You decrypt with the public key and vice versa. So they're interchangeable. And usually what they do in practice is they create a session key. So they do this exchange of key, this key exchange. And then they create a session key, which is just a simple key to encrypt and decrypt everything the same way. And this is what we call session token. Yeah, okay, great. So tls tls goes with tcp and it's also used ssl. Have you heard of ssl before? I think I've heard of it, but I don't really know. Often stands for secure socket layer. And what it is, is basically it's a way of authenticating. So for example, let's say you have a website, Hey, and you want to show everyone that you exist, right? Then you're gonna or that you're legit, then you're going to have a certificate and that certificate is going to be done, is going to be issued by an authority, a ca authority. And this ca authority will certify the certificate and when, for example, computer c. When a user U connects to website a, then it's going to receive a certificate that I can then check at the certificate authority, get back a response and verify that the website is correct. That's ssl. So you get a certificate to approve the authenticwebsite. And so when you apply to the ca authority. Need to do your name, your address, etcec to prove that you're a real person and you're not a scammer or something, and then they will certify your website. So that covers chapter two. Okay, this is boring to be honest. Yeah your Internet was broken Yeah my Internet cut out sorry about that. And my router is new. I wonder what is happening Yeah unfortunate they haven't installed even a fiber optic yet on my on my box and got have to do it myself kind of sucks but Yeah anyway, so what this is is it's one big Ethernet cable. Imagine this is one big Ethernet cable then you're gonna to have problems if a transmits at the same time as e on an Ethernet cable, what could happen? The data gets mixed. Yes. Problem. So how do we solve it? Use many ethercases. Yeah, that's the obvious solution. But let's say you're in the 19 nineties and you can't do that, and you are cie and you make a syllabus for 2025 and you still include this, right? And then maybe you need a separate solution. The solution that they found back then was csmcsmslash cd, csma slash cd. And what this is, is it's basically carrier sense. Let me write it down, carrier sense, let me bring out to the ething carrier sense multiple access collision detection. We'll access slash collision section right? And so what this is basically is a way to not transmit data at the same time. So how does this work? It's pretty simple. You the buffer and then sense it later. Yeah. Yeah. So let's say your computer a your transmit. And then computer d is like, okay, I want to transmit. So but first I want to check transmit. If transmitting, so yes, someone transmitting, then wait. And then once you've finished waiting, transmit. Now the important thing is, is for csma slash md. It's a cd, the transmit window. Doubles. Okay, great, let me check that. Yeah and so you have different types of collision, but I don't think you need that looking at the Wikipedia page. So I don't think it's useful. Yeah. Okay. Let me look through because this is not very interesting to be honest with you. So let me look through all the syllabus for something more interesting here. You know all the gright logic gyeah. Including things like exor. Yeah, Yeah, I know of them, okay? You know how to make a truth table, you know? Okay. Do you know about memory data register, memory address register, the accumulator index register? No, I don't know that specific of that. Do. Okay, we can do that. If it's quite interesting for you, I can go into more detail about the cpu. Cpu. Is that okay with you? Yeah. All right. So how what do you know about the cpu so far? I know you've done this already, but let's go over it again. There's a control unit. There's either 32 bit or 64 bit registers. Yep, there's a instruction counter. Yep. Those. Says he haell you hell you. And cash is cash. I think that's where the temporary registers stay, right? That's yes, that's separate orary memory yet. Okay, so you have several parts of a memory. So this is from the Cambridge cie, so I'm just going to draw them out. So you've got the pc and I'll tell you what it is, but that's program counter. You've got the mdr, the memory data register. This stores the memory basically stores the data of the next execution to be executed. You've got the memory access register, the address of the next piece of data to fetch from memory, memory address register, the accumulator, acc accumulator. You've got the index register, ir index register, and you've got the ciwhich is the current index, the current instruction register, and you've got the status register. These are the status registers. Then you've got what's called the bus. So actually, let me move memory address register to here. It's why it's the data line that connects everything. Yes. And but this is what we call the cpu bus. So this is the cpu bus, as you said, connects everything here. And so the peculiarities. For example, let's say you buy a 32 bits register, then your bus is 32 bits long. Yeah, 64 bit register, 64 bit. Its long for an eight bit computer, itbe eight bits long. But let's say it's 64 bits. It's here. Okay, what else is there? There's also here what we call the data the data bus. Now the data bus is kind of more special because it's only connected to the mdr. So I'm gonna to connect it here. You've got gom this and this will connect now this will connect like this ram, this is the data bus. Right, because it connects to the mdr, it fetches the next instruction basically. And then you've got the control register, status register. This is basically Yeah, I mean, it's it's basically the controlled unit is basically the status unit because this is it's kind of still the same control unit, the control unit. Do you know do you remember what that was? And puwhat's instruction to a center where more fundamentally than that, do you remember. No. So it's very simple. The control register is a wrong m code. Basically it's read only memory. And what it does, it's a piece of ram of read only boots up the system. It boots up the system that separates. Actually, there's two roms. There's a realms that the rom that boots up the system, you're right. But there's another one, which is this control unit. And actually this is very interesting. There's a guy called Benny eater. Have you seen Ben eater? No, this is really cool. If this interests you, search up as YouTube channel. I can't send you links because this, this, I just can't but or share my screen. But Ben eater, I was a big fan of him back in high school. He built his own eight bits computer, and he shows step by step. He connects all the wires, and he builds his own computer from scratch. It's awesome. And now he sells like eight big computer kits, but so that man will explain to you better how computer works than anybody else in the world. I promise you can search up his videos, they're an hour long, but he's got a very soothing voice. So if you're feeling like watching something or playing a video game while you've got his voice in the background and he's like talking about computers, he literally shows the wires that he connects. So give him a search. Ben eater, very interesting. But what the seep dcu the control unit does is it takes in literally a number. So because it's a 32 bit bus, it's going to get a 32 bit number. So it gets a 32 or a 64 bit number, right? So processes that to nowhere, this process esses and send the appropriate information to the appropriate units or the appropriate action. Exactly. So let's just add the cu here. It's really the status, but it's not really the same. But exactly, this is gonna connect to the ir is gonna connect to the accumulator, right? It's gonna connect to the Mar, it's gonna connect to the to the status regiit's connects to everything really. And basically it's just an instruction set that's already done, right? And this is a plus one for the program counter cr, maybe fetch, maybe load. And you've got you actually have code like I've written to cpu code wherelike for example, ldra 64, 64 for example, and literally immediate low register a 64Yeah exactly. It loads a 64 and literally what happens when you do this is it says, okay let's say you've got I add the registers here, but here you've got the mdr and the Mar. So what this does ldr let's say has the value usually it's in hex so maybe it has H six, right? Which I don't know hex by heart, but it has value H six. And in a what that will do is it will say, imagine you have one line of code and it's just this. Then what it's going to do is first program counters is at zero. So program counter is at zero grades. So it's going to go zero zero goes here to the bus. The bus goes to the memory address register. Boom goes to the memory address register here. It says, okay, I need to fetch, I need to basically fetch the item at zero. Sorry not mamy bad. Forget mathe cithe current instruction register. So it goes here and it says, okay, fetch whatever is at zero. Line zero it says, okay, I'm gonna ask, I'm gonna load that puts out the address in the bus. Bus gets sent to Mar. Mar is like, all right, this connected to databbus as well. Data. Oh, sorry, this is the address bus, not a data bus, by the way. Tell me if you're lost. I'm jumping all around. But this is the address bus. And what this does is it says load this, right? So this this cu, basically this low day is a lot of instructions. Basically it's ink, right? Which means increment the counter. Once you've incremented the counter load cr, so puts that counter instruction into Cir. This is the basic of each instruction. This is executed. And once it's in the Cir, it says, okay, transmit that to the it reads the instruction, the cu, right? So read. And then it reads the the instruction to cu and it says, okay, put it inside the Mar load, inside the mdr, right, the address at zero and execute. That's how it loads each item inside of the mdr, inside of the cu. And once it's executed, then it will do something like, okay, we need to load a so if you have a register here a, let's say you got register here b then these are connected, then it will put the value 64 inside of the accumulator 64. What it does is a zero plus 64, and then that is then input inside of a on the bus. Was that confusing? Because I went to bits everywhere here. It will take some time for me. But I think I got the basics of it, okay? The idea is this. There's only there is never any collision on the bus. Because there's is only one this. Now that statement is already false. For modern computers, there's multiple buses, but in general, rule thm is there's only one bus. Respect the bus basically. And so these calculations happen very, very quickly. And so the hertz, have you seen cpu? Hertz? Yeah, it's like 44 ghz or whatever. What that means is the bus is moving things at 44 ghz. So which means 44 million times per second, that's what it's doing. This 44 million instructions per second being executed on the database average because it depends on the instruction, of course, but that's what happens on the on the register. So ciis the current instruction register. This is the current construction to be executed. Mar is the memory access, memory address register, next address to fetch from ram. The mdr is memory. Sorry, this is a bit boring, but I have to do it. Data register, which is, is the data from the address. Acc equals accumulator? Which is similar to the alu, but has a slightly different a slightly different thing. What it does is it basically works with the alu. And what do I mean by this? Let's say, for example, the da, the acc and the alu work together. So if you've got the acc, the cumulator, it's basically like a register. And the alu, let's say, you're performing this operation. Four int I equals zero I less than ten I plus plus right for the Yeah then I would be put in the accumulator. So for example, the aou would say, okay, zero plus one, right? Then it would put the result in the accumulator one, right? But if you know you're going to reuse this address almost immediately later, then itbrief feed that right back inside of here. And so that was repefeed it one and it's two and I'll give it back two and it's three. So it's basically a way of speeding up operations by storing the immediate results in case you need to keep doing calculations. Does mean the accumulator is a set of registers. It's kind of like a register. Let me find you the cie definition. Yeah. Is it one or like many registers? I think it's one register, but in reality, it's probably multiple registers. Let me make sure about that, though. In reality, it's almost always different. Yeah so it's really just imagine it as one register and basically it temporarily holds the result of the alu after the logic operation. It's kind of like the memory of the calculator, if that makes sense. So it stores the result of the alu and it can be refed back into the alu because the alu in itself doesn't really store anything, right? It just does stuff just so this is a good way of thinking about it. This, for I and I example, is a good way of thinking about it. Or you can just think about it as the results register. And this will hold the results, hold the results. Okay. So you've got the alu accumulator, you've got the Cir, which is a currenconstruction register. And this is basically current address of current instruction being executed. If that's just the address of the current instruction to be executed. Pc, you know this already, program counter. And the status register. I'm actually not too sure what that is. Let me check that for you. Let's instore the flag from the alu. Yeah my actually, I think it's that it's basically whether Yeah, I think you're totally right. No, it's like if it was negative or something, Yeah was result negative, positive, floating, etc. Okay, nice. Yeah we've got that under control crm rmdr 60x and then you've got the ram. You know what that is wrong. You know what that is as well. And actually you have, you actually have several you've got the now don't think about it. You've got the zero flag, Carry flag. Yeah, that's negative. Is that a then? Yeah. So basically, I mean, you can, you've already know this. I think with Yeah, if the calculation result was zero, if there was a carrier, if it was negative, Yeah. P, very cool. So you've got that under control. Okay. So that's that's the the hard part of the a level in cpu immediate access. You know how the alu works, control unit works, you know system clock, you got that immediate access store. Never seen it in my life. What is that? Do you know what the immediate access store is? Maybe. It stores the wait store some immediate way, immediate value that might think that for some years late. I don't know. Yeah, it seems like it's just more registers to be honest. Okay. So just see it as a bunch of registers that are together, show understanding of how data transferred between various that's the bus, the data bus and the control bus. So the address bus transfers addresses, the data bus transfers data and the control bus transfers control signals. So I think you're good on that one. And actually it's very interesting and I really recommend you to watch a Ben eater for this. The way it works is by stop closing gates with power. So the way it works is they're literally they cut power to the gates to stop them from performing operations. Yeah and with be muand stuff with the what mux I think mux I Yeah I haven't heard of that but I just when I was watching his videos and everything he would close the gates and have like a closed gates basically a just a big and gates for everything Yeah Yeah it's just called the muit takes in two inputs three inputs, one side input and two direct inputs and well, it closes the gate depending on the site input. Nice. I think you're good. I think you're ready for this exam. Okay, great. So processor type in number of cores. Do you know what a core is in a cpu? Yeah. One like one processing unit. Cool. I told you about bus width and clock speed already. Cache memory. Yeah. You've got that. Usb. Hdmi, you know what that is? Hdmi, high definition media. Is it media? Multimedia. Multimedia. Interyeah. Well, you're good. Vga, have you heard of that? Have you seen it before? Vga. Vga. It's back in on not even my day, but earlier. That is the video graphics array. I not seen it. Yeah, that's that's a good thing. You don't want to encounter that. That's not fun. Graphics array. Okay, basically it's another type of hdm I port. Fetch execute cycle. Okay. You know the fetch execute cycle. Yeah it feches the instruction and. Decodes or reads it and then I execuuse it. What is the decode part? Basically sending the control unit, sending the data to the other parts? Yes, sending data exactly. I mean, you've understood it all here, the control net selling data. And again, this is basically from the ram chip. And the best way to think of that is like a dictionary or like a map, right? So it's basically a map. Yeah you got this address and where it's like a number to a sequence of instructions. Great. Okay, something a bit more interesting. Do you know what an interrupt is? No. So let's say you're on your computer, and let's say you've got Python running on one on one screen, you've got class in running on another screen, and then chrome running on a third screen or on three different applications running on your computer, probably like you do right now. The way it works is your computer is going to assign or the operating system for windows is going to assign most of the processing to the window you have open. I mean, that makes sense, right? Probably we have focus exactly. So hopefully you have class in focused right now. And then that would have youhave the cpu focusing mostly on class in, right? Yeah and this is done via interrupt. So again, you remember I've shown this a lot. You've got the ram right? And the ram has different blocks reserved for different things. So this might be class in. This might be your favorite Minecraft world. Maybe this is, I don't know, a video game. And you've got these things filling up your your ram. Now, an interrupt. What it does is you've got, imagine your your your cpu as one unit. Cpu, it's processing data. And the way it processes data is very different. You have different types of strategies. Now, if you want to run things, you have different ways you can do. You can do fifo. What does fifo stand for? I think we talked about this already. I don't know. No worries. It's first in, first out. Yes, first out. That's a queue is basically a queue. And so for example, let's say you've got task one, task task two. Task three, then it will do task one first, then task two, then task three. Now let me ask you, if you have t one task, let's go t one, t two. T and t three, and let's give it to t four, right? If I asked you, Henry, t one takes two cycles. T two takes eight cycles. T three takes four. T four takes three. What's the best way of executing these? What order is the best to execute these items? To the fastest first and the slowest last. Why I like that. Not a test, by the way. I'm not trying to but explain your reasoning. Let's see. Let's see why I think it just takes at least amount of time like that, would it though? If you execute two first, then three, then four, then eight, I still count 17s, right? And if I do two, then eight, then four, then three, I also count 17s. Yeah. So is that the optimal thing? I'm here to tell you that no, it's not. And the reason it's not, it's because there's no way to know what's the optimal way of running these tasks because you have no idea how important these tasks are and you don't know if there's interdependencies, right? So running tasks in a certain order, you don't need the amount of time it takes, you do. But you also need something else, which is called priority. Priority p. Obviously, if you're sending an email, you would prioritize your email being sent out a lot quicker than, for example, diagnostics, running antivirus software, running on your computer, or let's say you are playing a video game. You're much more interested in the next frame being calculated than you are receiving your latest emails, right? So that's how you prioritize them. So now if I give you these values, right, priority three, 31, 32, 34, what's the best now? What's the best execution? T two, t three and t one, then t four, t two, t three, t, what did you say? Then T, T one, t one, and then t four, t four. Why those ones? It's according to priority from low to high. That's but now I would make a different argument for you. Now let's look at this, right? T one is the first priority and t two is the first priority, right? And it's also the cheapest, the most expensive, but it's not priority number one. So let's do this one first, t two first, then let's look, we've got priority number two takes four, but priority number three takes two, right? So which is actually more important here because you can probably get more important things done quicker by quickly finishing t two, t one over t three. If I do t one next, then yes, I've not done the next most important thing, but I've done the third most important thing at double the speed, because instead of taking four cycles, it took me two. So there's an argument to be added to the type, the time complexity. Well, what I'm saying here is like if we it depends how we value the priority, right? We just ordered these priorities, but is it truly enough? Because just giving it a list of pridoesn't really tell you, right? Let's say, for example, task two is your first priority and it's it's because I don't know, you sent an email. Obviously, you want that to be complete as quickly as possible. And let's say that t three is the second priority. But it's something like open new tab, open tab, right? That's your second priority. Like I send the email and open a new tab. But let's say that t one is something like garbage, clean. Clean right on chrome, then I would really, really argue that you would rather do t one before t three because t one could make t three quicker since it's a garbage clean and then you can open the tab quicker and just have a better prioritization. So I would say that ordinal prioritization, I don't know if I'm making sense. I'm making sense here. Like it's I know it's kind of okay. Okay. So and we call this the prioritization problem. I'm not going to try and write this, but prioritization problem. And this problem is something that's worth literally millions of dollars, right? When when we do trading, when we do algoto try and trade, or when we quite simply do literally anything in government or in debbt, or just in Google algorithms, recommendation algorithms, it all comes down to prioritization and its definition, right? This is like the million dollar question is, how do you prioritize things and how do you value how much of a priority things are? And you can use lots of definitions. You can use like the amount of time it takes. You can use, obviously, the worthiness to the user. You can calculate how much it's worth to the user, the savings you can do. You can also calculate how much these calculation costs. And so you can get very deep inside inside of this. All that to say, there's no one way of doing it, right? Usually what computers do is they assign a priority value from zero to 99, or more accurately, from zero to 200, 56, 255, right? Where zero is top, priority in 255 is at least prioritized. Prioritized. And this is done on Linux. You can actually see it when you do n Proc, you can see the lists and the priority values. And so this is usually multiplied by time. Yeah and it's also got a conditional flag. Conditionality. For example, if t one depends on t three then t three needs to go first. It's obvious, right? You can't run t one until you have t three. Okay, let me quickly talk about that then. So you have fifa first in first sucks. We hate that. Then you have another thing called round Robin. Round Robin assigns, for example, five cycles to each task. So let's say, let's bring back our example here. So quickly select this like this. Let's say you've got this. What it does is it does five cycles of each task. So you'll do this theydo two cycles, then here itdo five, then here itdo four, here itdo three, and then here itdo three more at the end, right? So we'll go. T one, this is asking exam questions. I'll go t one, t two, three, four, and then I'll go back to two, right? That's the order of execution. That's round Robin. Then it's random. Which, well, you can guess how that goes. I'm not going to explain it. It sucks. And then you have priority. Where you have the zero to 255 and you multiply that with the time usually, but there's a different definition depending on the problem. But times, other factors. And then you can do priority plus round Robin. Where you reclathe task based on priority, then you do around Robin on these tasks and you give an equal share of time. And then there's also proportional round Robin, which is, sorry, I'm boring you now. But it has to be said, you've got a list of tasks that you've ranked from most important to least important, and you spend most of the time on the most important tasks. And less time on the least important tasks is proportionality round Robin. Yeah. And these are important because that's how you make sure every task works. And now that we've talked about that, I could get on two interruptions, but we're getting to the end of the class and I've given you a lot of information, a lot to think about. The first thing I wanna ask you, Henry, is we've got these classes scheduled later on. And so you seem to be interested in the a level course. I'd like to continue that with you, but I want to get it from you. Like what what do you find useful about these classes and what do you enjoy and what do you not enjoy it, right? You're allowed not to enjoy it and not like it as well. I mean, I'm getting a lot of information and which I find useful, and that's what I like. I still, I mean, I don't know what I don't like about these. It might be a little fast paced, but I think with some revision after I can after the class, I think I can manage it. I don't want you to revise after class. If you need me to slow down, tell me to slow down and I'll reexplain things. I really don't want you to be pulling hours from my classes. I'm not that interesting. I do think the content is useful for you for as level a level, but I don't want you to be doing extra work outside of class. You you should not be be having to do that. So if you need me to slow down and do it anyways for Oh my, okay. How are your costs sses going? Is everything okay? Do you need any help there? Yeah, it's okay. All right. Okay. So you just want to study the a level class, no other things. Statistics. Ml, not to fno, maybe that's also, but I think I would prioritize on a level subjects. Okay, Yeah, makes sense. Then I'll read the curriculum and we can focus on those one by one. Make sure you know everything. And again, if I'm going too fast, just interrupt me because I sometimes I start talking and I don't stop. So just tell me, Paul, I don't understand. Try again and and I'll listen to you. Okay, Yeah. But still, I think apart from the yellow subject, it's good to learn more outside of the curriculum. I completely agree. And I can I have other skill sets too, like career coaching. I know you want to go into physics, so I'm less useful there. But if ever you want na go into a computer science field and into some kind of it, I can tell you which jobs are high paying, what things to go, where to go. I think that's quite interesting too. But of course, that no pressure, it depends on you, of course, and your parents. Cool. All right. Well, have a great week. Yeah, thank you, sir. Rabbit, next week. See you.