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

    def insert(self, x):
        if x < self.val:
            if self.left == None:
                self.left = Node(x)
            else:
                self.left.insert(x)
        elif x > self.val:
            if self.right == None:
                self.right = Node(x)
            else:
                self.right.insert(x)

    def has(self, x):
        if x < self.val and self.left != None:
            return self.left.has(x)
        elif x > self.val and self.right != None:
            return self.right.has(x)
        if self.val == x:
            return True
        else:
            return False



def find_CA(root,a,b): #finds Common Ancestor
    if root.val > a and root.val > b:
        return find_CA(root.left,a,b)
    elif root.val < a and root.val < b:
        return find_CA(root.right,a,b)
    return root


def distance_to(root, x):
    if root.val == x:
        return 0
    elif root.val > x:
        return 1 + distance_to(root.left, x)
    return 1 + distance_to(root.right, x)


def total_distance(root, a, b):
    if root.has(a) and root.has(b):
        root = find_CA(root, a, b)
        return distance_to(root, a) + distance_to(root, b)
    else:
        if not root.has(a):
            return ("Tree does not contains node " + str(a))
        elif not root.has(b):
            return ("Tree does not contains node " + str(b))

##test##
#creates tree
tree = Node(8)
for i in [3,10,1,6,14,7,13]:
    tree.insert(i)

#              8
#            /    \
#         3          10
#       /   \          \
#      1     6           14
#              \         /
#                7     13
#

print(total_distance(tree, 13, 7))
print(total_distance(tree, 7, 13))
print(total_distance(tree, 1, 7))
print(total_distance(tree, 10, 13))
print(total_distance(tree, 6, 13))
print(total_distance(tree, -6, 13))
for i in range(15):

    print(i, tree.has(i))
###