from collections import *
from LowestCommonAncestor import *

def find(root, value):
    current_node = root

    while current_node:
        if current_node.data == value:
            return current_node
        elif value < current_node.data:
            current_node = current_node.left
        else:
            current_node = current_node.right

    return None

def main(root, input2, input3):
    lca = lowest_common_ancestor(root, find(root, input2), find(root, input3))
    
    if lca:
        return lca.data
    
    return -1