No one should be judged on the letter their name starts with. And personalities shouldn't be simplified into the categories of just "mean" or "nice". You should get to know the person yourself or get socializing help.
Cool.
Courteous is a synonym of nice. Courteous is a synonym of nice.
if you mean what country starts with a C, Cuba
Cornflower is nice. The color is beautiful.
if you mean what country starts with a C, cuba
call. to call someone.
converse.
If you are referring to capital "C", is starts for the element carbon.
collaborate
caribou
Examples of adverbs that start with C used to modify the verb to run are:casuallycautiouslycarelesslyconvincinglycrazilycalmlyclumsily
A Chocolate Cake perhaps ?!?