So, do you remember when we first learned about if else statements? We explored how these show up in our real lives by looking at simple card games like, a deck of cards and the game we're going to play is, we are going to pull up turn up a card if it's red, then I went to your team on point, if it's not, then we over the other team on point. So, the question we want to ask here is, in that game, how many different times do we need to check that one particular card in order to know what to do? We only need to check one thing, is it red? We could have chosen check is it black, but we don't have to check is it red and then if it's not, then we have to go check it's black because we know the cards in a car deck are either red or black. Those are your only two options. There's a lot of things that we play in terms of games or other situations in our life where there are only two options. Let's look at a couple. For example, we could flip the coin. It's going to come up heads or tail. No landing on side. Or if you're thinking of a video game where you're shooting based game. You either hit the target, or you missed the target. But sometimes there's games that have three possible options. Suppose we're thinking about rock-paper-scissors and we wanted to be able to identify which of the three you had put down. So, let's walk through that. Well, first you could ask, is it paper? If the answer to that was no, then we're going have reduced it down to two other options, but we'd still have to ask another question. Is it rock? For example. If that wasn't the case, then we'd be down and we'd know that in fact it was definitely scissors. So, when we have the three, we only ended up having to ask two questions in order to figure out for certain whether you had put down paper or rock or scissors. So, what does the diagram or flow chart, as we learned to make it, look like for selecting rock-paper-scissors? So, the key thing that we want to take away from that is that again to get ourselves to differentiate between three options when there are only three options available, we only need two different checks, that's why you saw two different diamonds on there. So, we're going to have you explore how you would design flowcharts to use the least number of checks to figure out some various options in the world. We'll give you some that you'll be able to choose one of your own design if you want. So, for example, if we have a stoplight, it's only got three options. It's either red, yellow, or green. We won't go with the whole European and other countries where sometimes the red, yellow come on at the same time. Just red, yellow or green. But we also might have something with a few more options based on your score, if it's greater than 90, maybe an A, if it's between 80 and 90 you get a B, 70 80 a C, 60 and 70, below 60 an F. So, we cover the whole number range or at least the whole reasonable number range, maybe for grading, and there is just five different options that we could give people in terms of a grade. Here's a slightly more complex one, this is a great fine by the way of searching out nested ifs in real life. So, this is a very US centric age span. Let say if you're less than 16, you can't drive. Then once we've eliminated that less than 16 debt, then we can check if you're between 16 and 18, you can't vote. Then once we know you're not less than 15 and you are not between 16 and 18, then we can check if you are between 18 and 25, in the United States is very hard to rent a car without paying upstream amounts of money. So, this is really difficult. Then if you're not any of those, then theoretically you could do it all. I don't know. It's just one way of looking at things. You can imagine coming up with various scenarios around this. So, the whole idea being that if we have a fixed number of options that we want to select between and how many checks do we need to make it there. So, by the way, we welcome even more complex situations. Maybe you want to come up with a more complex decision tree where after you've eliminated one, you can't even decide where you really are, you might need to ask some more questions before you can finally get there. So, we're going to allow you your choice in the next assignment of what kind of a decision tree or set of decisions you wanted to implement to figure out something of interest to you. So, the key thing is, you're going to need to choose a condition or a situation, and you're going to have to describe that in English. So, this could be a stoplight, it could be a grading system, you could modify my grading system and make something super spiffy with pluses and minuses or whatever but you'll be able to set a situation that you want, and make a flow chart with that.