#include <algorithm>
#include <cassert>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <utility>
#include <vector>

#define REP(i,s,n) for(int i=(int)(s);i<(int)(n);i++)
#define DEBUGP(val) cerr << #val << "=" << val << "\n"

using namespace std;
typedef long long int ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef pair<int, int> PI;

const int N = 100100;
VI g[N];
set<int> dp[N]; // children that players are able to win on
int dp_par[N];

int dfs1(int v, int par) {
  int can_win = 1;
  for (int w: g[v]) {
    if (par == w) continue;
    int res = dfs1(w, v);
    if (res == 1) {
      dp[v].insert(w);
    }
    can_win &= 1 - res;
  }
  return can_win;
}

void dfs2(int v, int par, int par_result) {
  for (int w: g[v]) {
    if (par == w) continue;
    bool incl = 0;
    if (dp[v].size() == 0 || (dp[v].size() == 1 && dp[v].count(w))) {
      incl = 1;
    }
    dfs2(w, v, incl && !par_result);
  }
  dp_par[v] = par_result;
}

int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  REP(i, 0, n - 1) {
    int a, b;
    cin >> a >> b;
    a--, b--;
    g[a].push_back(b);
    g[b].push_back(a);
  }
  dfs1(0, -1);
  dfs2(0, -1, 0);
  VI can_win;
  REP(i, 0, n) {
    if (dp[i].size() == 0 && dp_par[i] == 0) {
      can_win.push_back(i);
    }
  }
  if (0) {
    REP(i, 0, n) {
      cerr << "dp[" << i << "]:";
      for (int w: dp[i]) cerr << " " << w;
      cerr << endl;
      DEBUGP(dp_par[i]);
    }
  }
  cout << can_win.size() << endl;
  for (int v: can_win) cout << v + 1 << endl;
}