/in/foo.cc: In function 'int main()':
/in/foo.cc:30:9: warning: unused variable 'sum' [-Wunused-variable]
 int A,B,sum=0,i;
         ^~~
/in/foo.cc:30:15: warning: unused variable 'i' [-Wunused-variable]
 int A,B,sum=0,i;
               ^