/in/foo.cc: In function 'int main()':
/in/foo.cc:26:8: warning: unused variable 'x' [-Wunused-variable]
  int n,x,y,i,j;
        ^
/in/foo.cc:26:10: warning: unused variable 'y' [-Wunused-variable]
  int n,x,y,i,j;
          ^