While we are more than willing to help those that are stuck, that doesn't mean that we are here to do it all for you! We can't do all the work, you are either getting paid for this, or it's part of your grades and it wouldn't be at all fair for us to do it all for you.
So we need you to do the work, and we will help you when you get stuck. That doesn't mean we will give you a step by step solution you can hand in!
Start by explaining where you are at the moment, and what the next step in the process is. Then tell us what you have tried to get that next step working, and what happened when you did.
Think about how you would do it manually: you would create a list of all possible "pairs" for each set, and then look for matches across all three: So I'd start by thinking about how to do that. Hint: once you have assembled the pairs, sorting each set makes comparing them a lot easier!
Or maybe you'd look for all the matching numbers in all three sets, and then assemble pairs from that.
Part of the point of the task is to get you thinking about how to solve problems - so get thinking!
If you are having problems getting started at all, then this may help:
How to Write Code to Solve a Problem, A Beginner's Guide[
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