#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;

int main() {
	int N, M; cin >> N >> M;
	bool flag = false;
	for (int i = 0; i < N; i++) {
		string s;
		cin >> s;

		for (int j = 0; j <= M - 4; j++) {
			if (s.substr(j, 4) == "LOVE")flag = true;
		}
	}

	cout << (flag ? "YES" : "NO") << endl;
	
	return 0;
}