foo.cc:3:1: error: stray '`' in program
 ```cpp
 ^
foo.cc:3:2: error: stray '`' in program
 ```cpp
  ^
foo.cc:3:3: error: stray '`' in program
 ```cpp
   ^
foo.cc:3:4: error: 'cpp' does not name a type
 ```cpp
    ^~~

正在同步测试数据，请稍后
自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。