#include <iostream>
#include <vector>
#include <stack>

using namespace std;

int n, m;
vector <int> g[100010];
int color [100010];
bool fl = false;
stack <int> st1;
stack <int> st2;

void dfs (int v)
{
    color[v] = 1;
    st1.push(v);
    for (int i = 0; i < g[v].size() ; i++)
    {
        if (fl) break;

        int u = g[v][i];
        if (color[u] == 0)
        {
            dfs(u);
        }
        else
        {
            if (color[u] == 1)
            {
                fl = true;
                int k = st1.top();
                st1.pop();
                st2.push(k);
                while (k != u)
                {

                    k = st1.top();
                    st1.pop();
                    st2.push(k);
                }
            }
        }
    }
    color[v] = 2;
    if (!st1.empty())
    {
        st1.pop();
    }
}

int main()
{
    cin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int a, b;
        cin >> a, b;
        g[a - 1].push_back(b - 1);
    }

    for (int i = 0; i < n; i++)
    {
          color[i] = 0;
    }

    for (int i = 0; i < n; i++)
    {
        if (fl) break;
        if (color[i] == 0)
        {
            dfs(i);
        }
    }
    if (!fl)
    {
        cout << "NO";
    }
    else
    {
        cout << "YES" << endl;
        while (!st2.empty())
        {
            cout << st2.top() << " ";
            st2.pop();
        }
    }
    return 0;
}