//johnsjava.webs.com

import java.util.*;

public class NameNode
{
	public NameNode left = null;
	public NameNode right = null;
	public String name = "";

	public NameNode(String n)
	{
		name = n;
	}

	public int getLength()
	{
		return name.length();
	}

	public void add(NameNode nn)
	{
		if((left == null) && (nn.getLength() < getLength()))
		{
			left = nn;
		}
		else if((left != null) && (nn.getLength() < getLength()))
		{
			left.add(nn);
		}
		else if((right == null) && (nn.getLength() >= getLength()))
		{
			right = nn;
		}
		else if((right != null) && (nn.getLength() >= getLength()))
		{
			right.add(nn);
		}
	}

	public ArrayList<NameNode> getList()
	{
		ArrayList<NameNode> names = new ArrayList();
		if(left != null)
		{
			names.addAll(left.getList());
		}
		names.add(this);
		if(right != null)
		{
			names.addAll(right.getList());
		}
		return names;
	}

	public String toString()
	{
		return name;
	}

	public static void main(String[] args)
	{
		Scanner keyboard = new Scanner(System.in);
		NameNode top = new NameNode(keyboard.nextLine());
		while(true)
		{
			System.out.println(top.getList());
			top.add(new NameNode(keyboard.nextLine()));
		}
	}

}