foo.cc: In function 'int main()':
foo.cc:56:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   56 |     scanf("%d%d",&n,&k);
      |     ~~~~~^~~~~~~~~~~~~~
foo.cc:59:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   59 |      scanf("%d%d",&x,&y);
      |      ~~~~~^~~~~~~~~~~~~~

Found 20 testcases.
[Hydro](https://hydro.ac)提供评测服务