#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <map>
#include <queue>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using namespace std;

template<class T>
constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int n, m;
    cin >> n >> m;
    int p = 0;
    for (int i = 0; i < n; ++i) {
        string s;
        cin >> s;
        for (int j = 0; j < m-3; ++j) {
            if(s.substr(j, 4) == "LOVE") p++;
        }
    }
    cout << (p ? "YES\n" : "NO\n");
    return 0;
}