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

int main(){
    int n, m;
    cin >> n >> m;
    for(int i = 0; i < n; i++){
        string s;
        cin >> s;
        for(int i = 0; i < s.size() - 3; i++){
            if(s.substr(i, 4) == "LOVE"){
                cout << "YES" << endl;
                return 0;
            }
        }
    }
    cout << "NO" << endl;
}