#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];
	}
	bool ok = false;
	for (int i = 0; i < n; i++){
		for (int j = 0; j <= m - 4; j++){
			if (s[i].substr(j, 4) == "LOVE"){
				ok = true;
			}
		}
	}
	if (ok){
		cout << "YES" << endl;
	} else {
		cout << "NO" << endl;
	}
}