/in/foo.cc: In function 'int main()':
/in/foo.cc:14:17: warning: unused variable 'j' [-Wunused-variable]
   14 |         long i, j, n, k, t, x,sum;
      |                 ^
/in/foo.cc:14:23: warning: unused variable 'k' [-Wunused-variable]
   14 |         long i, j, n, k, t, x,sum;
      |                       ^