#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <stdio.h>
#include <vector>
#include <queue>
using namespace std;

vector< vector<int> > G;
vector<int> used;
vector<int> answ;
int flag = 0;
int start;

void DFS (int v) {
  printf("v = %d\n", v);
  used[v] = 1; // 1 - gray 2 - black
  for (int i = 0; i < G[v].size(); i++) {
    if (flag == 1) {
      answ.push_back(v + 1);
      printf("continue\n");
      return;
    }
    int to = G[v][i];
    printf("to = %d \n", to);
    if (used[to] == 1) {
      start = to;
      printf("RAISE FLAG curr %d start %d\n", v, start );
      flag = 1;
      break;
    } else {
      if (used[to] == 0) DFS (to);
    }
  }
  used[v] = 2;
  if (flag == 1) {
    printf("curr %d start %d\n",v , start );
    printf("PUSH\n" );
    answ.push_back(v + 1);
  }
}

void topsort(int V) {
  for (int i=0; i < V; ++i) {
    if (!used[i] && !flag) {
      printf("START DFS (%d)\n", i);
      DFS (i);
    }
  }
}

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

  int V, E;
  fin >> V >> E;

  G.resize(V);
  used.resize(V, 0);

  int i, j, x, y;
  for (i = 0; i < E; i++) {
    fin >> x >> y;
    G[x-1].push_back(y-1);
  }

  topsort(V);

  if (!flag) {
    fout << "NO";
  } else {
    fout << "YES" << endl;
    for (int i = 0; i < answ.size(); i++) {
      fout << answ[i] << ' ';
    }
  }

  return 0;
}