foo.cc: In function 'int main()':
foo.cc:24:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
foo.cc:30:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   30 |         scanf("%d",&a[i].f);
      |         ~~~~~^~~~~~~~~~~~~~
foo.cc:40:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |         scanf("%d",&a[i].mc);
      |         ~~~~~^~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务