class Node: def init(self, val): self.value = val self.right = None self.left = None

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

def insert(self, root, val):
    if root is None:
        return Node(val)
    elif val < root.value:
        if root.left is None:
            root.left = Node(val)
        else:
            self.insert(root.left, val)
    else:
        if root.right is None:
            root.right = Node(val)
        else:
            self.insert(root.right, val)
    return root

def inorder(self, root):
    if root is None:
        return 
    self.inorder(root.left)
    print(root.value, end=' ')
    self.inorder(root.right)

n=int(input()) numbers = list(map(int,input().split()))

tree = Tree() tree.root = Node(numbers[0])

for number in numbers[1:]: tree.insert(tree.root, number)

Perform in-order traversal

tree.inorder(tree.root)