# Preorder traversal

# Root -> Left ->Right

class Node:

    def __init__(self, data):

        self.left = None

        self.right = None

        self.data = data

# Insert Node

    def insert(self, data):

        if self.data:

            if data < self.data:

                if self.left is None:

                    self.left = Node(data)

                else:

                    self.left.insert(data)

            elif data > self.data:

                if self.right is None:

                    self.right = Node(data)

                else:

                    self.right.insert(data)

        else:

            self.data = data

# Print the Tree

    def PrintTree(self):

        if self.left:

            self.left.PrintTree()

        print( self.data),

        if self.right:

            self.right.PrintTree()

    def PreorderTraversal(self, root):

        res = []

        if root:

            res.append(root.data)

            res = res + self.PreorderTraversal(root.left)

            res = res + self.PreorderTraversal(root.right)

        return res

root = Node(27)

root.insert(14)

root.insert(35)

root.insert(10)

root.insert(19)

root.insert(31)

root.insert(42)

print(root.PreorderTraversal(root))