/in/foo.cc: In function 'int main()':
/in/foo.cc:6:5: error: 'cin' was not declared in this scope
    6 |     cin >> a >> b;
      |     ^~~
/in/foo.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
  +++ |+#include <iostream>
    1 | using namespace std;
/in/foo.cc:7:5: error: 'cout' was not declared in this scope
    7 |     cout << a + b << endl;
      |     ^~~~
/in/foo.cc:7:5: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
/in/foo.cc:7:22: error: 'endl' was not declared in this scope
    7 |     cout << a + b << endl;
      |                      ^~~~
/in/foo.cc:1:1: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
  +++ |+#include <ostream>
    1 | using namespace std;