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.
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[
^] though to be honest, this doesn't look like a development question at all: it look like a logic problem to me and that's not something that is normally "solved" in any coding language directly.
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Oh, and solving it on paper took less than one minute - it probably took you longer to find this site and post the question ... so give it a try yourself ...
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