#include <iostream>

using namespace std;

int main() {
  int n, m, flg=0;
  cin >> n >> m;

  for (int i=0; i<n; i++) {
    string s;
    cin >> s;
    if (s.find("LOVE")!=string::npos) flg=1;
  }

  printf("%s\n", flg==1 ? "YES": "NO");
}