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.

How should i begin??

There are a couple approaches in c++ language:

1) if input is in the form of a std::string object, you can use it's find() method to determine if it contains any of the words, example:

2) The other way, using standard C style character arrays

Now if course you will have to change the above to check each of the words listed in your assignment, as well as all the other requirements which I did not mention.

And don't forget to include the appropriage header files.

I really don't know how to code it....could you help me...Please x10000. I have to hand it in soon. I will remember you forever! Please help me!

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.

Regards