将输入的字符串（字符串仅包含小写字母‘a’到‘z’），按照如下规则，

循环转换后输出：a->b,b->c,…,y->z,z->a；若输入的字符串连续出现两个字母相同时，

后一个字母需要连续转换2次。例如：aa 转换为 bc，zz 转换为 ab；当连续相同字母超过两个时，

第三个出现的字母按第一次出现算。-The input string (string contains only lowercase letters ' a'　to ' z' ), in accordance with the following rules, the cycle conversion output: a->　b, b->　c, ..., y->　z, z->　a　If the input string two consecutive letters are the same, the letter needs to convert two consecutive times. For example: aa convert bc, zz converted to ab　When more than two consecutive identical letters, the third letter that appears the first time by the operator.