/in/foo.cc: In function 'int main()':
/in/foo.cc:5:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |         cin>>a>>b;
      |         ^~~
      |         std::cin
In file included from /in/foo.cc:1:
/usr/include/c++/12/iostream:60:18: note: 'std::cin' declared here
   60 |   extern istream cin;           /// Linked to standard input
      |                  ^~~
/in/foo.cc:6:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    6 |         cout<<a+b;
      |         ^~~~
      |         std::cout
/usr/include/c++/12/iostream:61:18: note: 'std::cout' declared here
   61 |   extern ostream cout;          /// Linked to standard output
      |                  ^~~~