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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def update_tree(root, executed_acts, total_rew):
 """ Given the tree, a list of actions that were executed before the game ended, and a reward, update the tree so that the path formed by the executed actions are all updated to the new reward. """

    root.value = max(total_rew, root.value)
    root.visits += 1
    new_nodes = 0

    node = root
    for step, act in enumerate(executed_acts):
        if act not in node.children:
            node.children[act] = Node()
            new_nodes += 1
        node = node.children[act]
        node.value = max(total_rew, node.value)
        node.visits += 1

    return new_nodes