foo.cc: In function 'int main()':
foo.cc:46:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   46 | scanf("%d%d",&n,&m);
      | ~~~~~^~~~~~~~~~~~~~
foo.cc:48:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   48 | scanf("%d",&(a[i]));
      | ~~~~~^~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务