CF540A.Combination Lock

Scrooge McDuck keeps his most treasured savings in a home safe with a combination lock. Each time he wants to put there the treasures that he's earned fair and square, he has to open the lock.

The combination lock is represented by n rotating disks with digits from 0 to 9 written on them. Scrooge McDuck has to turn some disks so that the combination of digits on the disks forms a secret combination. In one move, he can rotate one disk one digit forwards or backwards. In particular, in one move he can go from digit 0 to digit 9 and vice versa. What minimum number of actions does he need for that?

史高治·麦克达克将他最珍贵的积蓄存放在家中的保险箱里，保险箱配备了一个组合锁。每次他想把通过正当手段获得的财宝存入其中时，都必须先打开这个锁。

该组合锁由 $n$ 个可旋转的圆盘组成，每个圆盘上标有数字 $0$ 至 $9$。史高治·麦克达克需要转动若干圆盘，使得各圆盘上显示的数字组合成一个秘密密码。在一次操作中，他可以将某个圆盘向前或向后旋转一位（即加 $1$ 或减 $1$，模 $10$ 运算）。特别地，一次操作即可从数字 $0$ 转到 $9$，反之亦然。那么，他最少需要多少次操作才能达成目标？

The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of disks on the combination lock.

The second line contains a string of n digits — the original state of the disks.

The third line contains a string of n digits — Scrooge McDuck's combination that opens the lock.

第一行包含一个整数 $n$（$1 \leq n \leq 1000$）—— 密码锁上圆盘的数量。

第二行包含一个长度为 $n$ 的数字字符串 —— 圆盘的初始状态。

第三行包含一个长度为 $n$ 的数字字符串 —— 史高治·麦克老鸭的密码，该密码可打开密码锁。

Print a single integer — the minimum number of moves Scrooge McDuck needs to open the lock.

输出一个整数——史高治·麦克达克打开锁所需的最少移动次数。

In the sample he needs 13 moves:

• 1 disk:
• 2 disk:
• 3 disk:
• 4 disk:
• 5 disk:

在该样例中，他需要 13 步：

• 1 个圆盘：
• 2 个圆盘：
• 3 个圆盘：
• 4 个圆盘：
• 5 个圆盘：