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.
import sys
import math

int_inp = lambda: int(input())
str_inp = lambda: input().strip()
list_flt = lambda: list(map(float, input().strip().split()))
list_int = lambda: list(map(int, input().strip().split()))
list_str = lambda: list(input().strip())

# sys.stdin = open("input.txt", "r")

n = int_inp()

a_lst = list_str()
b_lst = list_str()

moves = 0

for a, b in zip(a_lst, b_lst):
    a = int(a)
    b = int(b)
    if (a > b) and (a - b <= 4):
        moves += a - b
    elif (a > b) and (a - b > 4):
        moves += (9 % a) + b + 1
    elif (b > a) and (b - a <= 4):
        moves += b - a
    else:
        moves += (9 % b) + a + 1

print(moves)