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())
s1=input()
s2=input()
sum=0
for i in range(0,n,1):
    k1=ord(s1[i])-48
    k2=ord(s2[i])-48
    # print(str(k1)+" "+str(k2))
    if k1<k2:
        if k2-k1>(k1+(9-k2)):
            sum=sum+(k1+(9-k2))+1
        else:
            sum=sum+k2-k1
        # print(sum)
    else:
        if k1-k2>(k2+(9-k1)):
            sum=sum+(k2+(9-k1))+1
        else:
            sum=sum+k1-k2
        # print(sum)
print(sum)