foo.c: In function 'main':
foo.c:18:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   18 |     scanf("%d", &num);
      |     ^~~~~~~~~~~~~~~~~
foo.c:20:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   20 |         scanf("%d", &ele);
      |         ^~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务