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.
n = int(input())
s = input()
s1 = input()
c = 0
for i in range(len(s)):
    if s[i] == '1':
        d = abs(1 - int(s1[i]))
        d1 = abs(9 - int(s1[i])) + 2
        if d <= d1:
            c += d
        else:
            c += d1
    elif s[i] == '0':
        d = abs(9 - int(s1[i]))
        d1 = abs(1 - int(s1[i]))
        if d <= d1:
            c += d + 1
        else:
            c += d1 + 1
    elif s[i] == '9':
        d = abs(9 - int(s1[i]))
        d1 = abs(1 - int(s1[i])) + 2
        if d <= d1:
            c += d
        else:
            c += d1
    else:
       c += abs(int(s[i]) - int(s1[i]))
print(c)