src.c:1:3: error: initializer element is not constant
a=input();
^
src.c:2:3: error: initializer element is not constant
b=input();
^
src.c:3:3: error: initializer element is not constant
c=input();
^
src.c:4:11: error: expected expression before 'int'
sum=print(int(a) int(b) int(c));
^