// https://speakerdeck.com/camypaper/yukicoder-no-408?slide=16
// こういう random を使った解法身につけたいな
#include <array>
#include <iostream>
#include <random>
#include <vector>

int main() {
    using namespace std;
    int n, m;
    cin >> n >> m;
    vector<vector<int>> g(n);
    for (int _ = 0; _ < m; _++) {
        int u, v;
        cin >> u >> v;
        u--; v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    mt19937 rng(random_device{}());
    uniform_int_distribution<int> dist(0, 3);
    auto ok = [&]() -> bool {
        vector<int> col(n);
        for (int i = 0; i < n; i++) { col[i] = dist(rng); }
        vector dp(n, array<bool, 16>{});
        for (int v : g[0]) { dp[v][1 << col[v]] = true; }
        for (int b = 0; b < 16; b++) {
            for (int v = 0; v < n; v++) {
                if (!dp[v][b]) { continue; }
                for (int nv : g[v]) {
                    if (nv == 0) { continue; }
                    if (b >> col[nv] & 1) { continue; }
                    dp[nv][b | 1 << col[nv]] = true;
                }
            }
        }
        for (int v : g[0]) {
            if (dp[v][15]) { return true; }
        }
        return false;
    };

    for (int _ = 0; _ < 200; _++) {
        if (ok()) {
            cout << "YES\n";
            return 0;
        }
    }
    cout << "NO\n";
}