/in/foo.cc: In function 'int main()':
/in/foo.cc:5:6: warning: unused variable 'c' [-Wunused-variable]
  int c,s,a,b;cin>>a>>b;
      ^
/in/foo.cc:5:8: warning: unused variable 's' [-Wunused-variable]
  int c,s,a,b;cin>>a>>b;
        ^