N = int(input())
S = list(input())
T = list(input())
Sr = S[::-1]
cnt1, cnt2 = 0, 0
for i in range(N):
    if S[i] != T[i]:
        cnt1 += 1
    if Sr[i] != T[i]:
        cnt2 += 1
if Sr == T:
    cnt2 = 2

print( min(cnt1, cnt2) )