foo.c: In function 'main':
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    5 |  scanf("%d %d", &n, &k);
      |  ^~~~~~~~~~~~~~~~~~~~~~
foo.c:11:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   11 |   scanf("%d", &s[i]);
      |   ^~~~~~~~~~~~~~~~~~

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