#include <fstream>
#include <iostream>
#include <string>

int main() {

	//std::ifstream inf("Text.txt");	std::cin.rdbuf(inf.rdbuf());

	int a, b = 0;
	std::cin >> a >> b;

	bool flg = false;
	std::string str;

	for (int i = 0; i < a; i++) {
		std::cin >> str;
		if (str.find("LOVE") != std::string::npos) {
			flg = true;
		}
	}

	if (flg) {
		std::cout << "YES" << std::endl;
	}
	else {
		std::cout << "NO" << std::endl;
	}

	return 0;
}