#include "bits/stdc++.h"
using namespace std;

int main() {
	int N, M;
	string S;
	bool check = false;
	cin >> N >> M;
	for (int i = 0; i < N; i++) {
		cin >> S;
		for (int j = 0; j < M - 3; j++) {
			if (S.substr(j, 4) == "LOVE") check = true;
		}
	}
	if (check) cout << "YES" << endl;
	else cout << "NO" << endl;
}