/* 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 Node {
        Node left;
        Node right;
        int value;
        boolean set;
        public Node(int value) {
            this.value = value;
            set = true;
        }
        public Node(boolean set) {
            set = set;
        }
    }

    public static Node convertToTree(int[] arr) {
        if (arr.length == 0) { return null; }
        return cttHelper(arr, 0, arr.length-1);
    }

    public static Node cttHelper(int[] arr, int i, int j) {
        if (i==j) {
            return new Node(arr[i]);
        } else {
            int mid = (i+j) / 2;
            Node root = new Node(arr[mid]);
            root.right = cttHelper(arr, mid+1, j);
            if (mid-1 >= i) {
                root.left = cttHelper(arr, i, mid-1);
            }
            return root;
        }
    }

    public static void printTree(Node n) {
        if (n == null) { System.out.println("null"); return; }

        Queue<Node> q1 = new LinkedList<Node>();
        Queue<Node> q2 = new LinkedList<Node>();

        int d = getMaxDepth(n);
        int spacing = (int) Math.pow(2, d-1) * 4;

        q1.add(n);
        while (!q1.isEmpty()) {
            // Because we're adding dummy nodes, need to know when to quit
            if (d-- < 1) {
                break;
            }

            for (Node node : q1) {
                if (node.left != null) {
                    q2.add(node.left);
                } else {
                    q2.add(new Node(false));
                }
                if (node.right != null) {
                    q2.add(node.right);
                } else {
                    q2.add(new Node(false));
                }
            }

            if (q1.peek().set) {
                System.out.printf("%"+spacing/2+"d", q1.remove().value);
            } else {
                insertSpaces(spacing/2);
                q1.remove();
            }

            while(!q1.isEmpty()) {
                if (q1.peek().set) {
                    System.out.printf("%"+spacing+"d", q1.remove().value);
                } else {
                    insertSpaces(spacing);
                    q1.remove();
                }
            }

            while(!q2.isEmpty()) {
                q1.add(q2.remove());
            }

            spacing/=2;
            System.out.println();
        }
    }

    public static void insertSpaces(int d) {
        for (int i = 0; i < d; ++i) {
            System.out.print(" ");
        }
    }

    public static int getMaxDepth(Node n) {
        if (n == null) {
            return -1;
        }

        return getMaxDepthHelper(n, 0);
    }

    public static int getMaxDepthHelper(Node n, int d) {
        if (n == null) {
            return d;
        } else {
            int leftMaxDepth = getMaxDepthHelper(n.left, d+1);
            int rightMaxDepth = getMaxDepthHelper(n.right, d+1);
            return Math.max(leftMaxDepth, rightMaxDepth);
        }
    }

    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        int[] arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
        Node root = convertToTree(arr);
        printTree(root);
    }
}