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