#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

void solve() {
  int N, M;
  string s;
  cin >> N >> M;
  rep(i, 0, N) {
    cin >> s;
    if (s.find("LOVE") != s.npos) {
      cout << "YES" << endl;
      return;
    }
  }
  cout << "NO" << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  getchar();
}