#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
constexpr int INF = 1e9;
constexpr long long LINF = 1e17;
constexpr int MOD = 1000000007;
constexpr double PI = 3.14159265358979323846;

int main(){
    int n,m;
    cin >> n >> m;
    bool ok = false;
    rep(i,n){
        string s;
        cin >> s;
        rep(j,m-3){
            if(s.substr(j,4) == "LOVE") ok = true;
        }
    }
    cout << (ok?"YES":"NO") << endl;
    return 0;
}