#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define rep(i,s,e) for(int (i) = (s);(i) <= (e);(i)++)
int N,M;


int main(){
  cin >> N >> M;
  rep(i,0,N - 1){
    string s;
    cin >> s;
    rep(j,0,M - 4){
      if(s.substr(j,4) == "LOVE"){
        cout << "YES" << endl;
        return 0;
      }
    }
  }

  cout << "NO" << endl;
  return 0;
}