foo.c: In function 'main':
foo.c:22:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   22 |  scanf("%d%d%d", &n1, &n2, &n3);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:24:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   24 |   scanf("%d", &a1[i]);
      |   ^~~~~~~~~~~~~~~~~~~
foo.c:27:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   27 |   scanf("%d", &a2[i]);
      |   ^~~~~~~~~~~~~~~~~~~
foo.c:30:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   30 |   scanf("%d", &a3[i]);
      |   ^~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务