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 os, sys

ii = lambda : int(input())
si = lambda  : input()
li = lambda : list(map(int, input().split()))
lsi = lambda : list(map(str, input().split()))

try: sys.stdin = open(r"C:\Users\LIB-606\Desktop\input.txt",'r')
except : pass


import math


length = ii()
a = si()
b = si()
c = 0
for i,j in zip(a,b):

    first = abs(int(i)-int(j))
    second = abs(int(f'1{i}')-int(j))
    third = abs(int(i)-int(f'1{j}'))

    #print(first,second)

    m = min([first,second, third])
    c+=m
    #print(c)
print(c)






'''
import math

x = ii()
#sq = math.sqrt(x)
c = 0
for i in range(1,(x//2)+1):
    ans = divmod(x,i)
    if ans[0]==ans[1]:
        c+=1
    print(ans)
print(c)

'''

	 	  	 	 		  		  				 			   	