#include <iostream>
#include <cstring>

using namespace std;

int main(void) {
    int n, m;
    char str[51];
    bool flag = false;

	cin >> n >> m;
	for (int i = 0; i < n; i++) {
		cin >> str;
		for (int j = 0; j < m-3; j++) {
			if (strncmp(&str[j], "LOVE", 4) == 0) {
				cout << "YES" << endl;
				flag = true;
				break;
			}
		}
		if(flag) break;
	}
    if(!flag) cout << "NO"<< endl;
}