/in/foo.cc: In function 'int main()':
/in/foo.cc:16:15: warning: unused variable 'j' [-Wunused-variable]
   16 |     int i, t, j, k, n, ans=0;
      |               ^
/in/foo.cc:16:18: warning: unused variable 'k' [-Wunused-variable]
   16 |     int i, t, j, k, n, ans=0;
      |                  ^