/in/foo.cc: In function 'int main()':
/in/foo.cc:9:16: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'char*' [-Wformat=]
   scanf("%d",&c);
              ~~^
/in/foo.cc:7:7: warning: unused variable 'a' [-Wunused-variable]
   int a,b;
       ^
/in/foo.cc:7:9: warning: unused variable 'b' [-Wunused-variable]
   int a,b;
         ^