 Hey what's up everybody welcome back to the YouTube video and tutorial and now we're just cranking out the solution into our missing numbers challenge. So let's see we've got some possible numbers we can work with right so let's create a variable for that possible numbers let's make it a list of just those integers one three six and seven and now let's try and create all the possibilities or the possible combinations or permutations of those numbers. So to do that I'm going to use the iter tools library so we can import iter tools and then from that we should be able to say that possibilities equals iter tools dot permutations of all those possible numbers right. So now for each possibility in those possible numbers I'm sorry yeah in those possibilities we could print out what we're working with right now and now we just got a bunch of options to where those numbers can fall. Now let's actually fill them into that equation that we have up there let's get that as a string we can just say string equals and I'm just going to actually just put these all these numbers in here with the question marks treated as if they're part of the values four five six and then I'm going to actually have the statement be like a Boolean like equation or a statement we can really test. So these question marks are going to be filled in real soon they're just going to be replaced with the string replaced as to the possibilities of each of those numbers. So now we've got our string for us right so for in each possibility we actually can now loop through each number and have it fill through that string that we're creating. Let's actually get a new string to work with we'll base it off of the original string and now we can say for each number in each possibility we can say new string can equal the same string that we've been working with so new string will keep updating with each with each iteration of the numbers that we passed through we'll replace the question mark with the current number we're looking at and we'll just replace the first occurrence of the question mark so we don't overflow and we don't replace all of them. Now at the very end new string should have been filled through with all those possibilities right oh and we'll have to actually take each number as a string because right now we're saving these integers but we want to be able to replace them in a string as a string you know so now we print all these out and now we have a bunch of these possibilities well now we can just tell python hey take a look at that man let's eval that let's actually run through that evaluation and one of these will return true and that's the combination of the numbers we actually want to run with so if that returns true now we can print out the new string that we've worked with and that's our solution right there real simple seven right here one right here let's see six and a three at the very bottom here does that work for us let's take a look let's see two seven one eight plus three four five six gives us six seven one four huh cool looks like that's everything we wanted cool thanks for watching everybody hope you enjoyed this hope you understand that solution hope you cranked out something similar but sounds great all right thanks for watching everybody i'll see you in the next challenge