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())
a = int(input())
b = int(input())
a_list =[]
b_list =[]
count = 0
for i in range(n):
    k = n - (i + 1)
    t = 10**k
    la = a//t
    lb = b//t
    a = a - la*t
    b = b - lb*t
    a_list.append(la)
    b_list.append(lb)

for j in range(n):
    if abs(a_list[j]-b_list[j])<=5:
        count += abs(a_list[j]-b_list[j])
    else:
        count += (10 - abs(a_list[j]-b_list[j]))
    
print(count)
    