#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

const double PI = acos(-1);

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n, m;
  cin >> n >> m;
  bool ck = false;
  REP (i, n) {
    string s;
    cin >> s;
    ck |= ~s.find("LOVE");
  }

  cout << (ck ? "YES" : "NO") << endl;
  
  return 0;
}