#include <iostream>
using namespace std;

int main() {
	std::endl(std::operator<<(std::cout, "Hello World!"));
	std::operator<<(std::cout, "Hello World!").operator<<(std::endl);
	std::operator<<(std::operator<<(std::cout, "Hello World!"), '\n');
	std::operator<<(std::operator<<(std::cout, "Hello World!"), "\n");
	std::operator<<(std::operator<<(std::cout, "Hello World!"), string("\n"));
	return 0;
}