#include<iostream>
#include<string>
#include<vector>
#include<algorithm>

using namespace std;

int main() {

	string love = "LOVE";
	int n, m;
	cin >> n >> m;
	vector<string> str;
	str.resize(n);

	for (int i = 0;i < n;i++) {
		cin >> str[i];
		int index= str[i].find(love);
		if (index != -1) {
			cout << "YES" << endl;

			return 0;
		}
	}

	cout << "NO" << endl;
	

	return 0;
}