Read in one character from the user (this may be 'Y', 'y', 'N', 'n').
If the character is 'Y' or 'y' display "YES".
If the character is 'N' or 'n' display "NO".
No other character will be provided as input.
One character (this may be 'Y', 'y', 'N', 'n').
One word: either "YES" or "NO" (quotation marks excluded).