content: import java.util.*;
  import java.io.*;
  
  class Node {
      Node left;
      Node right;
      int data;
      
      Node(int data) {
          this.data = data;
          left = null;
          right = null;
      }
  }
  
  class Solution {
  
      // function to print level order traversal of given tree
      public static void levelOrder(Node root) {
        Queue<Node> queue= new ArrayDeque<>();
        queue.add(root);
        while(!queue.isEmpty()) {
          Node tempNode=queue.poll(); // poll() removes the present head
          System.out.print(tempNode.data+" ");
          if(tempNode.left!=null) // Enqueue left child
              queue.add(tempNode.left);
          if(tempNode.right!=null) // Enqueue right child
              queue.add(tempNode.right);
          } 
      }
  
      // function to insert data in the tree
      public static Node insert(Node root, int data) {
          if(root == null) {
              return new Node(data);
          } else {
              Node cur;
              if(data <= root.data) {
                  cur = insert(root.left, data);
                  root.left = cur;
              } else {
                  cur = insert(root.right, data);
                  root.right = cur;
              }
              return root;
          }
      }
  
      //main function
      public static void main(String[] args) {
          Scanner scan = new Scanner(System.in);
          int t = scan.nextInt();
          Node root = null;
          while(t-- > 0) {
              int data = scan.nextInt();
              root = insert(root, data);
          }
          scan.close();
          levelOrder(root);
      }	
  }