#include <bits/stdc++.h> #define ll long long #define ld long double #define sp ' ' #define en '\n' using namespace std; const int N = 1e5 + 2; const ll mod = 1e9 + 7; vector<int> adj[N]; int ans[N], sol; void Dfs(int s, int e) { for (auto u : adj[s]) { if (u == e) continue; Dfs(u, s); if (ans[u] == u) { swap(ans[u], ans[s]); sol += 2; } } } int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n; cin >> n; for (int i = 1; i < n; i++) { int u, v; cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } for (int i = 1; i <= n; i++) ans[i] = i; Dfs(1, 0); if (ans[1] == 1) { swap(ans[1], ans[adj[1][0]]); sol += 2; } cout << sol << en; for (int i = 1; i <= n; i++) cout << ans[i] << sp; cout << en; return 0; }