#include <stdio.h>
#include <iostream>
#include <cmath>
#include <vector>
#include <algorithm>

using namespace std;

class Graph {
private:
    vector<vector<int> > graph;
    int vertex;

public:
    Graph(vector<vector<int> > graph) : graph(graph) {
        vertex = graph.size();
    }

    bool dfs(int index, vector<int>& color, vector<int>& parent, int &_end, int &_start) {
        color[index] = 1;

        for (unsigned int i = 0; i < graph[index].size(); ++i) {
            int to = graph[index][i];

            if (color[to] == 0) {
                parent[to] = index;
                if (dfs(to, color, parent, _end, _start))  return true; //цикл нашелся
            }

            else if (color[to] == 1) {
                _end = index;
                _start = to;
                return true;
            }
        }

        color[index] = 2;
        return false;
    }

    bool find_cycle(vector <int> &cycle) {
        vector<int> color(vertex, 0);
        vector<int> parent(vertex, -1);
        int _start, _end;
        _start = -1;
        for (int i = 0; i < vertex; ++i)
            if(!color[i])
                if (dfs(i, color, parent, _end, _start))
                    break;
        if (_start == -1)
            return false;
        else {
            cycle.push_back(_start);
            for (int index = _end; index != _start; index = parent[index])
                cycle.push_back(index);
            reverse(cycle.begin(), cycle.end());
            return true;
        }

    }
};


int main()
{
    int vertex, edges;
    cin >> vertex >> edges;
    vector<vector<int> > matrix(vertex);

    for (int i = 0; i < edges; i++) {
        int to, from;
        cin >> from >> to;
        matrix[from - 1].push_back(to - 1);
    }

    Graph graph(matrix);
    vector <int> cycle;

    if (!graph.find_cycle(cycle)) {
        cout << "NO" << endl;
    } else {
        cout << "YES" << endl;
        for (unsigned int i = 0; i < cycle.size(); ++i)
            cout << cycle[i] + 1 << " ";
    }

    return 0;
}