#include <bits/stdc++.h>
using namespace std;

int main () {
    int n, m, flag = 0;
    string s;
    cin >> n >> m;

    for (int i = 0; i < n; i++) {
        cin >> s;
        if (s.find("LOVE") != std::string::npos) {
            flag = 1;
        }
    }
    cout << (flag == 1 ? "YES" : "NO") << endl;
    return 0;
}