此程序给出一个算法，用于计算当已知一个m叉查找树的先序和后序遍历序列后，存在多少种中序遍历可能。输入格式为m s1 s2，其中m表示m叉树，例子

2 abc cba 结果为4

2 abc bca 结果为1

10 abc bca 结果为45

13 abejkcfghid jkebfghicda 结果为207352860-this procedure is an algorithm, When used in the calculation of a known m Binary Search Tree and the first sequence after sequence preorder, the existence of the number of species may preorder. Input format for s1 s2 m, m m-tree said, Example 2 abc cba results abc bca 4 2 1 10 results for the abc bca results for a 45 13 bejkcfghid jkebfghicda results 207352860