#include #include #include using namespace std; const int maxn = 100005; vector graph[maxn]; int main() { int n; cin >> n; vector visited(n + 1, false); for(int i = 0; i < n - 1; i++) { int a, b; cin >> a >> b; graph[a].push_back(b); graph[b].push_back(a); } queue q; q.push(0); visited[0] = true; while(!q.empty()) { int node = q.front(); q.pop(); cout << node << " "; for(int i = 0; i < graph[node].size(); i++) { int neighbour = graph[node][i]; if(!visited[neighbour]) { visited[neighbour] = true; q.push(neighbour); } } } visited[n] = true; q.push(n); vector v; while(!q.empty()) { int node = q.front(); q.pop(); v.push_back(node); for(int i = 0; i < graph[node].size(); i++) { int neighbour = graph[node][i]; if(!visited[neighbour]) { visited[neighbour] = true; q.push(neighbour); } } } for(int i = v.size() - 1; i >= 0; i--) { cout << v[i] << " "; } return 0; }