/in/foo.cc: In function 'int main()':
/in/foo.cc:13:12: warning: unused variable 'j' [-Wunused-variable]
   13 |     int i, j, k, n, m;
      |            ^
/in/foo.cc:13:15: warning: unused variable 'k' [-Wunused-variable]
   13 |     int i, j, k, n, m;
      |               ^
/in/foo.cc:13:21: warning: unused variable 'm' [-Wunused-variable]
   13 |     int i, j, k, n, m;
      |                     ^