Main.cc: In function 'int main()':
Main.cc:21:9: error: 'cout' was not declared in this scope
   21 |         cout << sum << endl;
      |         ^~~~
Main.cc:1:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
  +++ |+#include <iostream>
    1 | using namespace std;
Main.cc:21:24: error: 'endl' was not declared in this scope
   21 |         cout << sum << endl;
      |                        ^~~~
Main.cc:1:1: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
  +++ |+#include <ostream>
    1 | using namespace std;