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

int main(){
    int n,m; cin >> n >> m;
    vector<string> s(n);
    for(int i=0;i<n;i++) cin >> s[i];

    string love = "LOVE";
    for(int i=0;i<n;i++){
        if(s[i].find(love) != string::npos){
            cout << "YES" << endl;
            return 0;
        }
    }
    cout << "NO" << endl;
}