骑士的移动 Knight Moves

题意翻译

输入8*8的国际象棋棋盘上的2个格子（列：a~h，行：1~8），求马至少多少步从起点（键盘输入的第一个位置）跳到终点（键盘输入的第二个位置）。感谢 @陶文祥提供的翻译。

题目描述

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=6&page=show_problem&problem=380 [PDF](https://uva.onlinejudge.org/external/4/p439.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA439/49281f2a839995de267463a506fc7b04652bcf4a.png)

输入输出格式

输入格式

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA439/f986ca9c080d4c2fa5952f61f878eaafe27fdf4b.png)

输出格式

![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA439/e3265edbb46489790ff00e32193564840a6de7fe.png)

输入输出样例

输入样例 #1

e2 e4
a1 b2
b2 c3
a1 h8
a1 h7
h8 a1
b1 c3
f6 f6

输出样例 #1

To get from e2 to e4 takes 2 knight moves.
To get from a1 to b2 takes 4 knight moves.
To get from b2 to c3 takes 2 knight moves.
To get from a1 to h8 takes 6 knight moves.
To get from a1 to h7 takes 5 knight moves.
To get from h8 to a1 takes 6 knight moves.
To get from b1 to c3 takes 1 knight moves.
To get from f6 to f6 takes 0 knight moves.