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.
length = int(input())

n = input()

m = input()

##flow = ''

moves = 0
for i in range(length):
    _startMoves = moves
##    flow += 'n: ' + n[i] + ' , m: ' + m[i]
    dif = abs(int(n[i]) - int(m[i]))
##    flow += ' , dif: ' + str(dif)

    if(dif > 5):
        if(int(n[i]) < int(m[i])):
            moves += int(n[i]) + 1
            n = n[:i] + '9' + n[i + 1:]
            dif = abs(int(n[i]) - int(m[i]))
            moves += dif
##            flow += ' , If 1 Activated , moves: ' + str(moves) + '(+' + str(moves - _startMoves) + ')\n'
        else:
            moves += int(m[i]) + 1
            m = m[:i] + '9' + m[i + 1:]
            dif = abs(int(n[i]) - int(m[i]))
            moves += dif
##            flow += ' , If 2 Activated , moves: ' + str(moves) + '(+' + str(moves - _startMoves) + ')\n'


    else:
        moves += dif
##        flow += ' , moves: ' + str(moves) + '(+' + str(moves - _startMoves) + ')\n'

##print(flow)

print(moves)