#include <cstdio>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <iostream>
#include <string>

#define rep(i,N) for(int (i)=0;(i)<(N);(i)++)
#define MOD 1000000007

using namespace std;

int powmod(int a, int b, int p) {
	if (b == 0)return 1;
	else if (b % 2 == 0)return (powmod(a*a, b / 2, p) % p);
	else return (powmod(a, b - 1, p)*a%p);
}

int factorialmod(int a, int p) {
	if (!a)return 1;
	else return a * factorialmod(a - 1, p) % p;
}

int main(){
	int N, M,count = 0;
	bool flag = false;
	cin >> N >> M;
	vector<string> a(N);
	rep(i, N)cin >> a[i];
	rep(i, N) {
		rep(j, M - 3) {
			if (a[i].substr(j, 4) == "LOVE")flag = true;
		}
	}
	if (flag)cout << "YES\n";
	else cout << "NO\n";
	return 0;
}