#include <bits/stdc++.h>
using namespace std;

int main()
{
int i;
int j;
int N;
int M;
string A;

	ios::sync_with_stdio( false );
	cin.tie( 0 );

	cin >> N;
	cin >> M;

	for( i = 0; i < N; i++ )
	{
		cin >> A;

		if( (int) A.find( "LOVE" ) >= 0 )
		{
			cout << "YES" << endl;

			return 0;
		}
	}

	cout << "NO" << endl;

	return 0;
}