#include<iostream>
#include<string>
#include<vector>
using namespace std;

int main(){
	int line_num;
	int line_length;
	cin>>line_num>>line_length;
	string templine;
	bool flag=false;
	for(int i=0;i<line_num;i++){
		cin>>templine;
		if(templine.find("LOVE")!=string::npos){
			flag=true;
			break;
		}
	}
	if(flag==true)cout<<"YES"<<endl;
	else cout<<"NO"<<endl;
	return 0;
}