class Node: def init(self, info): self.info = info
self.left = None
self.right = None self.level = None

def __str__(self):
    return str(self.info) 

class BinarySearchTree: def init(self): self.root = None

def create(self, val):  
    if self.root == None:
        self.root = Node(val)
    else:
        current = self.root

        while True:
            if val < current.info:
                if current.left:
                    current = current.left
                else:
                    current.left = Node(val)
                    break
            elif val > current.info:
                if current.right:
                    current = current.right
                else:
                    current.right = Node(val)
                    break
            else:
                break

""" Node is defined as self.left (the left child of the node) self.right (the right child of the node) self.info (the value of the node) """ def levelOrder(root): if not root: return queue = [root] while queue: cur = queue.pop(0) print(cur.info, end=" ") if cur.left: queue.append(cur.left) if cur.right: queue.append(cur.right)

tree = BinarySearchTree() t = int(input())

arr = list(map(int, input().split()))

for i in range(t): tree.create(arr[i])

levelOrder(tree.root)