#include <iostream>
#include <string>

int main(void){
	int N, M;
	std::cin >> N >> M ;
	std::string A;
	for (int i = 0; i < N; i++){
		std::cin >> A;
		if (A.find("LOVE") != std::string::npos){
			std::cout << "YES";
			return 0;
		}
	}
	std::cout << "NO";
	return 0;
}