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