#include <iostream>
using namespace std;

class Student {
public:
    void study() {
        cout << "Student is studying\n";
    }
};

class Teacher {
public:
    void teach(Student& s) {
        cout << "Teacher is teaching\n";
        s.study();
    }
};

int main() {
    Student s;
    Teacher t;

    t.teach(s);

    return 0;
}