n = int(input())
S = input()
T = input()

def solve(S,T,mod):
    count = 0
    for s,t in zip(S,T):
        if s != t:
            count += 1
    if count%2 == mod:
        return count
    else:
        return 10**10

ans = min(solve(S,T,0),solve(S[::-1],T,1))
print(ans)