#include <iostream>
#include <string>
using namespace std;
int main(){
	int n,m;
	cin>>n>>m;
	for(int x=0;x<n;x++){
		string S;
		cin>>S;
		if(S.find("LOVE")!=string::npos){
			cout<<"YES"<<endl;
			return 0;
		}
	}
	cout<<"NO"<<endl;
	return 0;
}