foo.cc: In function 'int main()':
foo.cc:6:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
6 | cin<<x1<<x2;
| ^~~
| std::cin
iostream:60:18: note: 'std::cin' declared here
foo.cc:10:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
10 | cout<<y1<<endl<<y2<<endl<<y3;
| ^~~~
| std::cout
iostream:61:18: note: 'std::cout' declared here
foo.cc:10:19: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
10 | cout<<y1<<endl<<y2<<endl<<y3;
| ^~~~
| std::endl
In file included from iostream:39:
/nix/store/hf2gy3km07d5m0p1lwmja0rg9wlnmyr7-gcc-12.3.0/include/c++/12.3.0/ostream:688:5: note: 'std::endl' declared here
688 | endl(basic_ostream<_CharT, _Traits>& __os)
| ^~~~
[Hydro](https://hydro.ac)提供评测服务