#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;

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