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A. Combination Lock
time limit per test
2 seconds
memory limit per test
256 megabytes
standard input
standard output

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?


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.


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


In the sample he needs 13 moves:

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