#include <bits/stdc++.h>
using namespace std;
vector<int> g[100005];
int sz[100005], answer[100005];
long long ans = 0;
vector<int> spis;
void clears(int v, int pr) {
  sz[v] = 1;
  int pos = -1;
  for (int i = 0; i < (int)g[v].size(); i++) {
    int u = g[v][i];
    if (u == pr)
      pos = i;
    else {
      clears(u, v);
      sz[v] += sz[u];
    }
  }
  if (pos != -1) {
    swap(g[v][pos], g[v].back());
    g[v].pop_back();
  }
  return;
}
void dfs(int v, int len) {
  ans += (long long)2 * len;
  spis.push_back(v);
  for (int i = 0; i < (int)g[v].size(); i++) {
    int u = g[v][i];
    dfs(u, len + 1);
  }
  return;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  for (int i = 1; i < n; i++) {
    int u, v;
    cin >> u >> v;
    g[u].push_back(v), g[v].push_back(u);
  }
  clears(1, -1);
  int cen = 1;
  while (true) {
    int mx = -1;
    for (int i = 0; i < (int)g[cen].size(); i++) {
      int u = g[cen][i];
      if (2 * sz[u] > sz[cen]) mx = i;
    }
    if (mx == -1) break;
    int newcen = g[cen][mx];
    swap(g[cen][mx], g[cen].back());
    g[cen].pop_back();
    g[newcen].push_back(cen);
    sz[cen] -= sz[newcen];
    sz[newcen] += sz[cen];
    cen = newcen;
  }
  dfs(cen, 0);
  cout << ans << '\n';
  if (n % 2 == 0) {
    for (int i = 0; i < n / 2; i++)
      answer[spis[i]] = spis[i + n / 2], answer[spis[i + n / 2]] = spis[i];
  } else {
    for (int i = 1; i < n / 2; i++)
      answer[spis[i]] = spis[i + n / 2], answer[spis[i + n / 2]] = spis[i];
    answer[spis[0]] = spis[n / 2], answer[spis[n / 2]] = spis[n - 1],
    answer[spis[n - 1]] = spis[0];
  }
  for (int i = 1; i <= n; i++) cout << answer[i] << ' ';
  cout << '\n';
  return 0;
}
