You might already be familiar with binary. For example, this is 1. 1 is equivalent to 5 in decimal. That's because this is the ones place, this is the twos place, fours place, eights place, 16, 32, 64, and 128. We have a 1 in the fourth place and a 1 in the ones place. 4 plus 1 is 5, so this is fine. But how might we represent a negative number? So let's say we wanted to represent negative 5. Well, there are a couple ways we can do that. One way is to take this 128 place and instead of using that as the 128 place, use that as a sign. So change this to a 1 here to indicate that this is negative. And then the rest of it is the same, 1 1. So this would be 5 here. And then instead of this representing 128, it represents that the number is negative. So negative 5. Now, of course, it's important to know how many bits you're working with, right? Because if we're only using 4 bits, then a 5 would be 1 1. That's equal to 5. But then we're going to use this top bit here. In this case, we're only using 4 bits, so the top one is this fourth bit. And so negative 5 might be 1 1 1. And instead of this being the eights place, this is actually representing a sign. So this would be negative 5, and this would be 5. So it's important to know how many bits you're working with so that you know which bit is the first bit and therefore which bit indicates what the sign of the number is. So to keep going with this example, we can look at just regular counting in...