import java.util.ArrayList;

import java.util.Scanner;

// Create by Inho 2018. 4. 27.

// 1991 트리순회

public class Study_1991 {

static class Node {

char left;

char right;

}

static Node[] Nodes;

static void preorder(char root){

if (root == '.') return;

else {

System.out.print(root);

preorder(Nodes[root-'A'].left);

preorder(Nodes[root-'A'].right);

}

}

static void inorder(char root){

if (root == '.') return;

else {

inorder(Nodes[root-'A'].left);

System.out.print(root);

inorder(Nodes[root-'A'].right);

}

}

static void postorder(char root){

if (root == '.') return;

else {

postorder(Nodes[root-'A'].left);

postorder(Nodes[root-'A'].right);

System.out.print(root);

}

}

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

int N = scanner.nextInt();

scanner.nextLine();

Nodes = new Node[N];

for(int i=0;i<N;i++){

Nodes[i] = new Node();

}

for(int i =0;i<N;i++){

String input = scanner.nextLine();

String token[] = input.split(" ");

Nodes[token[0].charAt(0)-'A'].left = token[1].charAt(0);

Nodes[token[0].charAt(0)-'A'].right = token[2].charAt(0);

}

preorder('A');

System.out.println("");

inorder('A');

System.out.println("");

postorder('A');

}

}