import sys
from collections import deque, Counter
sys.setrecursionlimit(5 * 10 ** 5)
from pypyjit import set_param
set_param('max_unroll_recursion=-1')
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 63 - 1
mod = 998244353
n = ii()
s = input()
t = input()

cnt = 0
for i in range(n):
    if s[i] != t[i]:
        cnt += 1

cnt2 = 0
for i in range(n):
    if s[n - i - 1] != t[i]:
        cnt2 += 1
print(min(cnt, cnt2))