using System;
using System.Collections.Generic;
class Program
{
	static void Main(string[] args)
	{
		string[] str = Console.ReadLine().Split();
		int N = int.Parse(str[0]);
		int M = int.Parse(str[1]);
		string ans = "NO";
		for(var i=0;i<N;i++){
			string str2 = Console.ReadLine();
			for(var j=0;j<M-3;j++){
				if(str2.Substring(j,4) == "LOVE"){
					ans = "YES";
					break;
				}
			}
		}
		Console.WriteLine(ans);
	}
}