Number of Leaf Nodes

class BinaryTreeNode:
    def __init__(self,data):
        self.data = data
        self.left = None
        self.right = None
def treeInput():
    rootData = int(input())
    if rootData == -1:
        return None
    root = BinaryTreeNode(rootData)
    leftTree = treeInput()
    rightTree = treeInput()
    root.left = leftTree
    root.right = rightTree
    return root
def PrintTree(root):
    if root == None:
        return
    print(root.data,end= ":")
    if root.left is not None:
        print("L", root.left.data, end = ",")
    if root.right is not None:
        print("R", root.right.data, end = "")
    print()
    PrintTree(root.left)
    PrintTree(root.right)

def NumLeafNOdes(root):
    if root is None:
        return 0
    if root.left == None and root.right == None:
        return 1
    numLeafLeft = NumLeafNOdes(root.left)
    numLeafRight = NumLeafNOdes(root.right)
    return numLeafLeft + numLeafRight
root = treeInput()
PrintTree(root)
print(NumLeafNOdes(root))