#include <iostream>
using namespace std;

class daynhauhoc {
	private: void say_hello() { cout << "hello\n"; }
	public: void do_nothing() { 
		daynhauhoc dnh;
		dnh.say_hello();
	}
};

int main() {
	daynhauhoc ltd;
	ltd.do_nothing();
	return 0;
}