foo.c: In function 'main':
foo.c:6:17: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  int n1, n2, i; scanf("%d%d", &n1, &n2);
                 ^~~~~~~~~~~~~~~~~~~~~~~
foo.c:8:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ^~~~~~~~~~~~~~~~~~
foo.c:10:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &b[i]);
   ^~~~~~~~~~~~~~~~~~

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