class Node: 
    def __init__(self, data): 
        self.data = data 
        self.left = None 
        self.right = None 
# Binary Search Tree Class  
class BST: 
    def __init__(self): 
        self.root = None 
    # Insert automatically using comparison 
    def insert(self, data): 
        if self.root is None: 
            self.root = Node(data) 
        else: 
            self._insert(self.root, data) 
    def _insert(self, node, data): 
        if data < node.data: 
            if node.left is None: 
                node.left = Node(data) 
            else: 
                self._insert(node.left, data) 
        elif data > node.data: 
            if node.right is None: 
                node.right = Node(data) 
 
            else: 
                self._insert(node.right, data) 
        else: 
            print("Duplicate value not allowed:", data) 
    # Traversals  
    def inorder(self, node): 
        if node: 
            self.inorder(node.left) 
            print(node.data, end=" ") 
            self.inorder(node.right)        
    def preorder(self, node): 
        if node: 
            print(node.data, end=" ") 
            self.preorder(node.left) 
            self.preorder(node.right)         
    def postorder(self, node): 
        if node: 
            self.postorder(node.left) 
            self.postorder(node.right) 
            print(node.data, end=" ") 
# Main  
tree = BST() 
while True: 
    print("\n===== Binary Search Tree =====") 
    print("\nMenu") 
    print("1 - Insert Node") 
    print("2 - Tree Traversals") 
    print("3 - Exit") 
 
    choice = int(input("Enter your choice: ")) 
    if choice == 1: 
        while True: 
            value = int(input("Enter value to insert: ")) 
            tree.insert(value) 
            cont = input("Do you want to insert more? (y/n): ").lower() 
            if cont != 'y': 
                break 
    elif choice == 2: 
        if tree.root is None: 
            print("Binary Search Tree is Empty") 
        else: 
             print("Inorder Traversal:") 
             tree.inorder(tree.root) 
             print("\nPreorder Traversal:") 
             tree.preorder(tree.root) 
             print("\nPostorder Traversal:") 
             tree.postorder(tree.root) 
    elif choice == 3: 
        print("Program exited") 
        break 
    else: 
        print("Invalid choice! Please try again.")