foo.c: In function 'main':
foo.c:19:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   19 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
foo.c:21:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   21 |   scanf("%d",&a[i]);
      |   ^~~~~~~~~~~~~~~~~

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