#include <bits/stdc++.h>
using namespace std;

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

int n, m;

int main() {
   cin >> n >> m;

   bool love = false;
   rep (i, n) {
      string s;
      cin >> s;
      if (s.find("LOVE") != string::npos) {
         love = true;
      }
   }

   puts(love?"YES":"NO");

   return 0;
}