#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); i ++)
using namespace std;
typedef long long ll;
typedef pair<ll,ll> PL;
typedef pair<int,int> P;
const int INF = 1e9;
const ll MOD = 1e9 + 7;
const double eps = 1e-6;

int main(){
    int N,M; cin >> N >> M;
    bool flag = false;
    rep(i,N){
        string S; cin >> S;
        rep(j,M - 3) {
            if (S.substr(j,4) == "LOVE") {
                flag = true;
                break;
            }
        }
        if (flag) break;
    }
    if (flag) cout << "YES" << endl;
    else cout << "NO" << endl;
}