n = int(input())
s = input()
t = input()
s = list(s)
t = list(t)
ss = list(s)
ss.reverse()
mae = 0
usi = 0
for i in range(n):
    if s[i] != t[i]:
        mae += 1
    if ss[i] != t[i]:
        usi += 1
if mae <= usi and mae % 2 == 0:
    print(mae)
elif usi <= mae and usi % 2 == 1:
    print(usi)
elif mae % 2 == 0:
    print(mae)
else:
    print(usi)