#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

bool dfs(int v, vector<int>& color, vector<vector<int>>& graph, vector<int>& p, int &cycleEnd, int &cycleSt) {
    color[v] = 1;
    for (int i = 0; i < graph[v].size(); ++i) {
        int to = graph[v][i];
        if (color[to] == 0) {
            p[to] = v;
            if (dfs(to, color, graph, p, cycleEnd, cycleSt))  return true;
        }
        else if (color[to] == 1) {
            cycleEnd = v;
            cycleSt = to;
            return true;
        }
    }
    color[v] = 2;
    return false;
}

bool find_cycle(vector<vector<int>>& graph, vector <int> &cycle) {
    int n = graph.size();
    vector<int> color(n, 0);
    vector<int> p(n, -1);
    int cycleSt, cycleEnd;
    cycleSt = -1;
    for (int i = 0; i < n; ++i)
        if(!color[i])
            if (dfs(i, color, graph, p, cycleEnd, cycleSt))
                break;
    if (cycleSt == -1)
        return false;
    else {
        cycle.push_back(cycleSt);
        for (int v = cycleEnd; v != cycleSt; v = p[v])
            cycle.push_back(v);
        reverse(cycle.begin(), cycle.end());
        return true;
    }

}

int main() {
    int n, m;
    cin >> n >> m;
    vector < vector<int> > graph(n);
    vector <int> cycle;
    for (int i = 0; i < m; ++i) {
        int firstV, secondV;
        cin >> firstV >> secondV;
        graph[firstV - 1].push_back(secondV - 1);
    }
    if (find_cycle(graph,cycle)) {
        cout << "YES" << endl;
        for (int i = 0; i < cycle.size(); ++i)
            cout << cycle[i] + 1 << ' ';
    }
    else
        cout << "NO";
    //system("pause");
    return 0;
}