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

int main() {
  int n, m;
  bool f = false;
  string s;
  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    cin >> s;
    if (!f && s.find("LOVE") != string::npos) f = true;
  }
  cout << (f ? "YES" : "NO") << endl;
  return 0;
}