foo.cc: In function 'void work()':
foo.cc:48:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:58:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&t,&k);
     ~~~~~^~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务