#include <iostream>
#include <vector>

using std::vector;

void DFS(int v, int p, vector<vector<int>>& neighbours, vector<std::string>& colour, vector<int>& parent, bool& flag) {
  parent[v] = p;
  colour[v] = "GREY";
  for (int to : neighbours[v]) {
    if (flag) {
      break;
    }
    if (colour[to] == "BLACK") {
      continue;
    }
    if (colour[to] == "GREY") {
      std::cout << "YES\n";
      flag = true;
      vector<int> cycle;
      int u = v;
      while (u != to) {
        cycle.push_back(u + 1);
        u = parent[u];
      }
      cycle.push_back(to + 1);
      for (int i = cycle.size() - 1; i >= 0; --i) {
        std::cout << cycle[i] << " ";
      }
      colour[v] = "BLACK";
      return;
    }
    DFS(to, v, neighbours, colour, parent, flag);
  }
  colour[v] = "BLACK";
}

int main() {
  int n, m;
  std::cin >> n >> m;
  vector<vector<int>> neighbours(n);
  vector<std::string> colour(n, "WHITE");
  vector<int> parent(n);
  for (int j = 0; j < m; ++j) {
    int l, r;
    std::cin >> l >> r;
    neighbours[l - 1].push_back(r - 1);
  }
  bool flag = false;
  for (int i = 0; i < n; ++i) {
    if (colour[i] == "WHITE") {
      DFS(i, -1, neighbours, colour, parent, flag);
      if (flag) {
        break;
      }
    }
  }
  if (!flag) {
    std::cout << "NO";
  }
}