foo.cc:36:1: error: stray ‘`’ in program
   36 | ```
      | ^
foo.cc:36:2: error: stray ‘`’ in program
   36 | ```
      |  ^
foo.cc:36:3: error: stray ‘`’ in program
   36 | ```
      |   ^
foo.cc: In function ‘int main()’:
foo.cc:5:5: error: ‘cout’ was not declared in this scope; did you mean ‘std::cout’?
    5 |     cout << "请输入三个整数：" << endl;
      |     ^~~~
      |     std::cout
iostream:63:18: note: ‘std::cout’ declared here
foo.cc:5:35: error: ‘endl’ was not declared in this scope; did you mean ‘std::endl’?
    5 |     cout << "请输入三个整数：" << endl;
      |                                   ^~~~
      |                                   std::endl
In file included from iostream:41:
/nix/gcc-13.3.0/include/c++/13.3.0/ostream:735:5: note: ‘std::endl’ declared here
  735 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
foo.cc:6:5: error: ‘cin’ was not declared in this scope; did you mean ‘std::cin’?
    6 |     cin >> a >> b >> c;
      |     ^~~
      |     std::cin
iostream:62:18: note: ‘std::cin’ declared here