foo.cc: In function 'void work()':
foo.cc:31:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   31 |     scanf ("%d %d",&n,&m);
      |     ~~~~~~^~~~~~~~~~~~~~~
foo.cc:33:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |         scanf("%d",&a[i]);
      |         ~~~~~^~~~~~~~~~~~
foo.cc:35:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |         scanf ("%d",&b[i]);
      |         ~~~~~~^~~~~~~~~~~~

正在同步测试数据，请稍后
Found 3 testcases.
[Hydro](https://hydro.ac)提供评测服务