foo.c: In function 'main':
foo.c:9:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    9 |     scanf("%d%d%d", &n1, &n2, &n3);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:15:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   15 |         scanf("%d", &a1[i]);
      |         ^~~~~~~~~~~~~~~~~~~
foo.c:17:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   17 |         scanf("%d", &a2[i]);
      |         ^~~~~~~~~~~~~~~~~~~
foo.c:19:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   19 |         scanf("%d", &a3[i]);
      |         ^~~~~~~~~~~~~~~~~~~

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