Bear in mind that your submitted entry for a CodeChef problem is not being looked at by a person; a computer program is assessing your output for matching exactly to the requirements. So no input prompts, no descriptive text around the results, and make sure text outputs if any are exactly as given, including matching upper and lower case.
The part of programming you can work on here is about making the algorithms work, and (eventually, hopefully) work efficiently. The part of programming concerned with giving good supporting information to users, validating values etc. isn’t really covered here, and establishing an accurate specification is mostly just a matter of reading the problem very carefully (and occasionally checking the sample output to clarify).