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.
#                          JAI SHREE RAM

import math; from collections import *
import sys; from functools import reduce

# sys.setrecursionlimit(10**6)
def get_ints(): return map(int, input().strip().split())
def get_list(): return list(get_ints())
def get_string(): return list(input().strip().split())
def printxsp(*args): return print(*args, end="")
def printsp(*args): return print(*args, end=" ")

UGLYMOD = int(1e9)+7; SEXYMOD = 998244353; MAXN = int(1e5)

# sys.stdin=open("input.txt","r");sys.stdout=open("output.txt","w")

# for _testcases_ in range(int(input())):
n = int(input())
s = input()
t = input()
ans = 0
for i in range(n):
    first = int(s[i])
    secon = int(t[i])
    diff = max(first, secon) - min(first, secon)
    ans += min(diff, 10-diff)
print(ans)

'''
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Link may be copy-pasted here if it's taken from other source.
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'''