: In function 'int main()':
:8:16: error: 'cin' was not declared in this scope
    8 |         while (cin >> year >> month >> day)
      |                ^~~
:1:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
  +++ |+#include <iostream>
    1 | using namespace std;
:32:25: error: 'cout' was not declared in this scope
   32 |                         cout << "Monday" << endl;
      |                         ^~~~
:32:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:32:45: error: 'endl' was not declared in this scope
   32 |                         cout << "Monday" << endl;
      |                                             ^~~~
:1:1: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
  +++ |+#include <ostream>
    1 | using namespace std;
:37:25: error: 'cout' was not declared in this scope
   37 |                         cout << "Tuesday" << endl;
      |                         ^~~~
:37:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:37:46: error: 'endl' was not declared in this scope
   37 |                         cout << "Tuesday" << endl;
      |                                              ^~~~
:37:46: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
:41:25: error: 'cout' was not declared in this scope
   41 |                         cout << "Wednesday" << endl;
      |                         ^~~~
:41:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:41:48: error: 'endl' was not declared in this scope
   41 |                         cout << "Wednesday" << endl;
      |                                                ^~~~
:41:48: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
:45:25: error: 'cout' was not declared in this scope
   45 |                         cout << "Thursday" << endl;
      |                         ^~~~
:45:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:45:47: error: 'endl' was not declared in this scope
   45 |                         cout << "Thursday" << endl;
      |                                               ^~~~
:45:47: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
:49:25: error: 'cout' was not declared in this scope
   49 |                         cout << "Friday" << endl;
      |                         ^~~~
:49:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:49:45: error: 'endl' was not declared in this scope
   49 |                         cout << "Friday" << endl;
      |                                             ^~~~
:49:45: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
:53:25: error: 'cout' was not declared in this scope
   53 |                         cout << "Saturday" << endl;
      |                         ^~~~
:53:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:53:47: error: 'endl' was not declared in this scope
   53 |                         cout << "Saturday" << endl;
      |                                               ^~~~
:53:47: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
:57:25: error: 'cout' was not declared in this scope
   57 |                         cout << "Sunday" << endl;
      |                         ^~~~
:57:25: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
:57:45: error: 'endl' was not declared in this scope
   57 |                         cout << "Sunday" << endl;
      |                                             ^~~~
:57:45: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?