/in/foo.cc: In function 'int main()':
/in/foo.cc:103:6: warning: unused variable 'x' [-Wunused-variable]
  int x,y,i,j;
      ^
/in/foo.cc:103:8: warning: unused variable 'y' [-Wunused-variable]
  int x,y,i,j;
        ^
/in/foo.cc:103:12: warning: unused variable 'j' [-Wunused-variable]
  int x,y,i,j;
            ^