How do I take inputs in my program??via files or terminal??

I just want to know how should i take inputs in my program??
If through files??What will be the file name??

Please read FAQ.

Codechef will run your program on each of the input files by redirecting the standard input stream to an input file, and the standard output stream to another file. The output generated by your program must match the correct output exactly in order to be judged correct.