static void Main() { SourceExpander.Expander.Expand(ignoreAnyError: false); var N = int.Parse(Console.ReadLine()); List <long[]> treeInfo = new List <long[]>(); for (int i = 0; i < N - 1; i++) { var AB = Console.ReadLine().Split().Select(long.Parse).ToArray(); treeInfo.Add(AB); } var dicNode = GraphUtil.CreateTree(treeInfo); List <long> history = new List <long>(); dicNode[1].IsArrive = true; Execute(dicNode[1], history); Console.WriteLine(string.Join(" ", history)); }