/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	static class TreeNode {
		TreeNode left;
		TreeNode right;
		int data;
	}
	public static TreeNode add(TreeNode node, final int value) {
		TreeNode insert = new TreeNode();
		insert.data = value;
		if (node == null) {
		    return insert;
        }
        TreeNode current = node;
		while (true) {
			if (value < current.data) {
				if (current.left == null) {
					current.left = insert;
					break;
				} else {
					current = current.left;
				}
			} else {
				if (current.right == null) {
					current.right = insert;
					break;
				} else {
					current = current.right;
				}
			}
		}
		return node;
	}
	private static void printTree(TreeNode node, String indent) {
		if (node == null) return;
		System.out.println(indent+node.data);
		printTree(node.left, indent+"  ");
		printTree(node.right, indent+"  ");
	}
	public static void main (String[] args) throws java.lang.Exception {
		TreeNode tree = null;
	    tree = add(tree, 5);
	    tree = add(tree, 3);
	    tree = add(tree, 1);
	    tree = add(tree, 4);
	    tree = add(tree, 8);
	    tree = add(tree, 6);
	    tree = add(tree, 9);
		printTree(tree, "");
	}
}