class Solution:
    """
    @param start: The start of the edges set
    @param end: The end of the edges set
    @return: Return the subtree count
    """
    def getSubtreeCount(self, start, end):
        # Write your code here
        children_dict = {}
        real_root = start[0]
        for node_index in range(len(start)):
            parent_node = start[node_index]
            child_node = end[node_index]
            if parent_node not in children_dict:
                children_dict[parent_node] = [child_node]
            else:
                children_dict[parent_node].append(child_node)
        def subtree_count(root_node, children_dict):
            if root_node not in children_dict:
                return [1, 0]
            else:
                non_root_tree_num = 0
                root_tree_num = 1
                for children_node in children_dict[root_node]:
                    child_root_tree_num, child_non_root_tree_num = subtree_count(children_node, children_dict)
                    non_root_tree_num += (child_non_root_tree_num + child_root_tree_num)
                    root_tree_num *= (child_root_tree_num + 1)
                return root_tree_num, non_root_tree_num
        output = subtree_count(real_root, children_dict)
        return (output[0] + output[1]) % 10000007