#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
template<class T> inline bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T&a,T b){if(a>b){a=b;return 1;}return 0;}
using ll = long long;

int n,m;
string s;

int main () {
    cin.tie(0); ios::sync_with_stdio(false); 

    cin >> n >> m;
    bool ok=false;
    while(cin >> s)rep(i,m-3) ok |= s.substr(i,4)=="LOVE";
    cout << (ok ? "YES" : "NO") << '\n';
}