everest% cc mutual.c
everest% 

everest% a.out
Type in a string (< 64 characters): Prof. Richard Chang
Input: Prof. Richard Chang
Alphabetic characters: 16
Other characters: 3
everest% 

everest% a.out
Type in a string (< 64 characters): 1000 Hilltop Circle, Baltimore MD 21250
Input: 1000 Hilltop Circle, Baltimore MD 21250
Alphabetic characters: 24
Other characters: 15
everest%