#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)

int main() {
  int n, m;
  cin >> n >> m;
  bool b = false;
  rep(_i,n) {
    string s;
    cin >> s;
    if(s.find("LOVE")!=string::npos) {
      b = true;
    } 
  }
  if(b) cout << "YES" << endl;
  else cout << "NO" << endl;
  return 0;
}