给定的字母表A 由26 个小

写英文字母组成A={a,b,…,z}。该字母表产生的升序字符串是指字符串中字母按照从左到

右出现的次序与字母在字母表中出现的次序相同，且每个字符最多出现1 次。例如，

a,b,ab,bc,xyz 等字符串都是升序字符串。现在对字母表A 产生的所有长度不超过6 的升序

字符串按照字典序排列并编码如下。

1 2 … 26 27 28 …

a b … z ab ac …

对于任意长度不超过6 的升序字符串，迅速计算出它在上述字典中的编码。

-Given the alphabet A by the 26 lowercase letters of the alphabet composed of A = (a, b, ..., z). Generated by the alphabet ascending string refers to the letter string in accordance with the order from left to right appears in the alphabet and letters appearing in the same order, and each character appears a maximum of 1 times. For example, a, b, ab, bc, xyz, etc. are ascending string string. Alphabet A have now all the length of not more than 6 strings of ascending order in accordance with the dictionary and coding sequence is as follows. 1 2 ... 26 27 28 ... ab ... z ab ac ... for any length of not more than 6 strings of ascending quickly calculate it in the dictionary encoding.