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[j]);
      |   ^~~~~~~~~~~~~~~~~
foo.c:21:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   21 |   scanf("%d",&b[j]);
      |   ^~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务