#include <iostream>
#include <vector>
using namespace std;

int n, m;
vector <vector <int> > graf;
vector <int> colours;
vector <int> cycle;

bool dfs(int v) {
    colours[v] = 2;
    for (int i = 0; i < graf[v].size(); i++) {
        if (colours[graf[v][i]] == 1) {
            if (dfs(graf[v][i])) {
                cycle.push_back(v);
                return true;
            }
        }
        else if (colours[graf[v][i]] == 2) {
            cycle.push_back(v);
            return true;
        }
    }
    colours[v] = 3;
    return false;
}

int main() {
    cin >> n >> m;
    graf.resize(n);
    colours.resize(n);
    int v1, v2;
    colours.assign(n, 1);
    for (int i = 0; i < m; i++) {
        cin >> v1 >> v2;
        graf[v1 - 1].push_back(v2 - 1);
    }
    int t = 0;
    for (int i = 0; i < n; i++) {
        if (colours[i] == 1 && dfs(i)) {
            t = 1;
            break;
        }
    }
    if (t == 0) cout << "NO";
    else {
        cout << "YES\n";
        for (int i = cycle.size() - 1; i >= 0; --i) {
            cout << cycle[i] + 1 << " ";
        }
    }
    return 0;
}