foo.c: In function 'main':
foo.c:23:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   23 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
foo.c:26:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   26 |   scanf("%d", &a);
      |   ^~~~~~~~~~~~~~~
foo.c:29:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   29 |  scanf("%d", &k);
      |  ^~~~~~~~~~~~~~~

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