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

int main() {
  int N, M;
  cin >> N >> M;
  for (int i = 0; i < N; i++) {
    string S;
    cin >> S;
    for (int j = 0; j < N; j++) {
      if (S.substr(j, 4) == "LOVE") {
        cout << "YES" << "\n";
        return 0;
      }
    }
  }

  cout << "NO" << "\n";
}