#include <bits/stdc++.h>

using namespace std;

int main() {
	int n, m;
	cin >> n >> m;

	string s[n];
	for (int i = 0; i < n; i++) {
		cin >> s[i];
	}

	bool ok = false;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j <= m-4; j++) {
			if (s[i][j] != 'L') {
				continue;
			}
			ok = ok || s[i].substr(j, 4) == "LOVE";
		}
	}

	if (ok) {
		puts("YES");
	} else {
		puts("NO");
	}

	return 0;
}