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

#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)

int main(){
    int n,m;
    cin>>n>>m;
    if(m<4){
        cout<<"NO"<<endl;
        return 0;
    }
    rep(i,0,n){
        string s;
        cin>>s;
        rep(j,0,m-4){
            if(s.substr(j,4)=="LOVE"){
                cout<<"YES"<<endl;
                return 0;
            }
        }
    }
    cout<<"NO"<<endl;

    return 0;
}