import sys
input = sys.stdin.readline

def f(s, t):
    return sum(1 if si!=ti else 0 for si, ti in zip(list(s), list(t)))

N = int(input())
S = input()[:-1]
T = input()[:-1]
ans = 10**18

if f(S, T)%2==0:
    ans = min(ans, f(S, T))

if f(S[::-1], T)%2==1:
    ans = min(ans, f(S[::-1], T))

assert(ans!=10**18)
print(ans)