foo.c: In function 'main':
foo.c:27:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   27 |     scanf("%d", &n);
      |     ^~~~~~~~~~~~~~~
foo.c:30:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   30 |         scanf("%d", a+i);
      |         ^~~~~~~~~~~~~~~~
foo.c:32:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   32 |     scanf("%d", &x);
      |     ^~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务