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.
t=int(input())
l=list(input())
l1=list(input())
t1=[]
t2=[]
for i in range(t):
    t1.append(int(l[i]))
    t2.append(int(l1[i]))

count=0
for i in range(t):
    if (t1[i]<=5 and t2[i]<=5) or (t1[i]>=5 and t2[i]>=5):
        count+=abs(t2[i]-t1[i])
    elif (t1[i]<5 and t2[i]>5):
        count+=(t1[i]-1)
        count+=2
        temp=9
        while(temp>t2[i]):
            count+=1
            temp-=1
    elif (t1[i]>5 and t2[i]<5):
        count+=(9-t1[i])
        count+=2
        temp=1
        while(temp<t2[i]):
            count+=1
            temp+=1
    
print(count)