/in/foo.cc: In function 'int main()':
/in/foo.cc:60:10: warning: unused variable 'l' [-Wunused-variable]
  int x,y,l,r;
          ^
/in/foo.cc:60:12: warning: unused variable 'r' [-Wunused-variable]
  int x,y,l,r;
            ^