#include<iostream>
#include<stdlib.h>
#include<string>

using namespace std;

int main()
{
    int n,m,flag=0;
    string s;
    cin>>n>>m;
    for(int i=0;i<n;i++){
        cin>>s;
        if(s.find("LOVE")!=std::string::npos){
            flag=1;
        }
    }
    cout<<(flag==1 ? "YES" : "NO" )<< endl;
    return EXIT_SUCCESS;
}