foo.cc: In function 'int main()':
foo.cc:23:21: warning: variable 'x' set but not used [-Wunused-but-set-variable]
   23 |                 int x;
      |                     ^

正在同步测试数据，请稍后
Found 10 testcases.
[Hydro](https://hydro.ac)提供评测服务