foo.c: In function 'main':
foo.c:17:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   17 |  scanf("%d %d", &n1, &n2);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~
foo.c:19:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   19 |   scanf("%d", &a[i]);
      |   ^~~~~~~~~~~~~~~~~~
foo.c:21:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   21 |   scanf("%d", &b[i]);
      |   ^~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务