src.c:1:9: error: empty character constant
a=input('')
^
src.c:1:3: error: initializer element is not constant
a=input('')
^
src.c:2:1: error: expected ',' or ';' before 'b'
b=input('')
^
src.c:2:9: error: empty character constant
b=input('')
^
src.c:3:9: error: empty character constant
c=input('')
^