在数据加密和数据压缩中常需要对特殊的字符串进行编码。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。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。-In data encryption and data compression is often the need for special encoded string. Given an alphabet A is composed of 26 small write English letters A={a, b,... , z}. Ascending the alphabet string generated refers to string letter in the alphabet and the letters appear in accordance with the order from left to right the same as the order, and each character appears at most 1 times. For example, a, B, AB, BC, XYZ strings are ascending string. For ascending strings of arbitrary length of not more than 6, quickly calculate it in the dictionary coding.