#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ul = unsigned long long;
using ld = long double;
const int N = 100001;
vector<int> g[N], li[N];
int d0[N], d1[N], mv[N], f[N], num[N], ans[N];
void dfs(int v, int p) {
  mv[v] = -1;
  for (int u : g[v]) {
    if (u == p) continue;
    dfs(u, v);
    d1[v] += min(d1[u], d0[u]);
    if (d1[u] < d0[u]) f[v] = 1;
    if (!f[v] && (mv[v] == -1 || d1[u] - d0[u] < d1[mv[v]] - d0[mv[v]]))
      mv[v] = u;
  }
  d0[v] = d1[v];
  if (!f[v]) {
    if (mv[v] == -1)
      d0[v] = N;
    else
      d0[v] += d1[mv[v]] - d0[mv[v]];
  } else
    mv[v] = -1;
  d1[v]++;
}
void rec(int v, int ip, int p) {
  if (ip)
    num[v] = num[p];
  else
    num[v] = v;
  li[num[v]].push_back(v);
  for (int u : g[v])
    if (u != p) rec(u, d1[u] < d0[u] || !ip && mv[v] == u, v);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, u, v;
  cin >> n;
  for (int i = 0; i < (n - 1); i++) {
    cin >> u >> v;
    u--;
    v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  dfs(0, -1);
  cout << d0[0] * 2 << '\n';
  rec(0, 0, -1);
  for (int i = 0; i < (n); i++)
    for (int j = 0; j < (li[i].size()); j++)
      ans[li[i][j]] = li[i][(j + 1) % li[i].size()];
  for (int i = 0; i < (n); i++) cout << ans[i] + 1 << ' ';
}
