#include<iostream>                          
 
using namespace std;
 
int main(){
  string str[100];
  int N, M;
  cin >> N >> M;
 
  for(int i =0;i < N; i++){
    cin >> str[i];
  }
 
  for(int i =0;i < N; i++){
    if(str[i].find("LOVE") != string::npos){
      cout << "YES" << endl;
      return 0;
    }
  }
 
  cout <<"NO"<< endl;
 
  return 0;
}