Good solutions, since we don't need to know which number stands for the character 'a':)

I used complex numbers too. This was the first method that crossed my mind since I major in physics. And I have to use elegant complex numbers even if the code works lower, haha! (Actually I don't know if it's true...)

你这评论只给自己人看啊O(∩_∩)O哈哈~也挺流弊的

There is always an amazing funciton that can solve my problem as easy as pie...