#include <bits/stdc++.h>

using namespace std;

using int64 = long long;

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