foo.c: In function 'main':
foo.c:14:6: warning: unused variable 'i' [-Wunused-variable]
   14 |  int i;
      |      ^
foo.c:13:6: warning: unused variable 'j' [-Wunused-variable]
   13 |  int j;
      |      ^
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    5 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d", &m);
      |  ^~~~~~~~~~~~~~~

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