foo.c: In function 'main':
foo.c:8:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    8 |     scanf("%s",s1);
      |     ^~~~~~~~~~~~~~
foo.c:9:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    9 |     scanf("%s",s2);
      |     ^~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务