#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
int main(void) {
	int n, m;
	cin >> n >> m;
	string s;
	bool ok = false;
	for (int i = 0; i < n; ++i) {
		cin >> s;
		if (s.find("LOVE") != std::string::npos)
			ok = true;
	}
	cout << (ok ? "YES" : "NO") << endl;
	return 0;
}