Noone will spoonfeed you any solutions. have a good attempt at the problem for yourself and come back if you get stuck on anything along with a description of whatever it is you need help with, and the code you've tried so far.
Seriously, how much do you think we care? Moreover, I hardly think so. I'm pretty sure that you won't hold gratitude or appreciation soon after you'll hand that assignment. Not that I'd pay a penny for you being eternally grateful to me.
Ancient Dragon already gave you a start. I'm feeling to give you just some general advices:
1 - Divide your program in steps - most common are input, processing and output but you can elaborate this further
2 - Write one step at a time, for example begin with a program that only accepts one string input and quits. Then try to solve the problem for simplest cases (i.e. the user enters "one" or "nine").
3 - Post your code. We will gladly help you (not for the glory, however) if you show us you do care enough. When I ask for help I think that the time of people more expert than me is more precious than mine. Consequently, I have to devote more time than they do in solving my problem. If I don't act this way, I won't learn anything. Try to think this way and you'll be surely helped.