#include <bits/stdc++.h>

using namespace std;

int main() {
	int n, m;
	cin >> n >> m;
	string s[60];
	for (int i = 0; i < n; i++) {
		cin >> s[i];
		if (s[i].find("LOVE") != string::npos) {
			cout << "YES" << endl;
			return 0;
		}
	}
	cout << "NO" << endl;
	return 0;
}