Given the tree below and nodes p=5 and q=1, what is the final returned node's value?

Consider the following code snippet implementing the parent pointer + ancestor set approach for Lowest Common Ancestor. Given the tree below and nodes p=5 and q=1, what is the final returned node's value? Tree structure: 3 / \ 5 1 / \ \ 6 2 8

def lowestCommonAncestor(root, p, q):
    parent = {root: None}
    stack = [root]
    while p not in parent or q not in parent:
        node = stack.pop()
        if node.left:
            parent[node.left] = node
            stack.append(node.left)
        if node.right:
            parent[node.right] = node
            stack.append(node.right)

    ancestors = set()
    while p:
        ancestors.add(p)
        p = parent[p]
    while q not in ancestors:
        q = parent[q]
    return q