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

int main(){
    int N,M;
    cin>>N>>M;
    vector<string> S(N);
    for(int i=0;i<N;i++){
        cin>>S[i];
    }
    
    bool LOVE = false;

    for(int i=0;i<N;i++){
        for(int j=0;j<(M-3);j++){
            string s = "";
            for(int k=j;s.size()<4;k++){
                s += (S[i])[k];
            }
            if(s == "LOVE") LOVE = true;
        }
    }

    if(LOVE) cout<<"YES\n";
    else cout<<"NO\n";

}