Quite a simple task - just to start learning strings...
Input data will contain a single string of small latin letters and few spaces.
Answer should contain the string of the same length with the same characters but in reverse order.
Example:
input data:
four score and seven years ago
answer:
oga sraey neves dna erocs ruof
Though some languages especially functional has built-in function for this, please try perform it on your own and 'in-place' i.e. moving characters of the same string instead of copying them to the new one.