#include <fstream>
#include <vector>
#pragma comment (linker, "/STACK:64000000")

using namespace std;

int n, m, fr, to;
vector<vector <int>> g;
vector<int> p;
vector<int> clr;
int cycle_end, cycle_st;
bool cycle = false;

void dfs(int v)
{
    clr[v] = 1;
    for (int i = 0; i <  g[v].size(); i++)
    {
        int a = g[v][i];
        if (clr[a] == 0)
        {
            clr[a] = 1;
            p[a] = v;
            dfs(a);
        }
        if (clr[a] == 1)
        {
            cycle_st = a;
            p[a] = v;
            cycle_end = v;
            cycle = true;
            break;
        }
    }
    clr[v] = 2;
}

int main()
{
    ifstream in("cycle.in");
    ofstream out("cycle.out");

    in >> n >> m;

    g.resize(n);
    p.resize(n);
    clr.resize(n);
    for (int i = 0; i < m; i++)
    {
        in >> fr >> to;
        g[fr - 1].push_back(to - 1);
    }

    for (int i = 0; (i < n)&&(cycle == false); ++i)
        if (clr[i] == 0)
            dfs(i);

    if (cycle == false)
        out << "NO";
    else
    {
        out << "YES" << endl;
        vector<int> cycle_v;
        cycle_v.push_back (cycle_st);
        for (int v = cycle_end; v != cycle_st; v = p[v])
            cycle_v.push_back (v);

        reverse (cycle_v.begin(), cycle_v.end());
        for (size_t i = 0; i < cycle_v.size(); ++i)
            out << cycle_v[i] + 1 << " ";

    }
    return 0;
}