/in/foo.cc: In function 'int main()':
/in/foo.cc:5:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    5 |     cout << a + b;
      |     ^~~~
      |     std::cout
In file included from /in/foo.cc:1:
/usr/include/c++/12/iostream:61:18: note: 'std::cout' declared here
   61 |   extern ostream cout;          /// Linked to standard output
      |                  ^~~~
/in/foo.cc:5:13: error: 'a' was not declared in this scope
    5 |     cout << a + b;
      |             ^
/in/foo.cc:5:17: error: 'b' was not declared in this scope
    5 |     cout << a + b;
      |                 ^