N = int(input()) S = input() T = input() ans = 10 ** 6 SS = S[::-1] tmp = 0 for i in range(N): if S[i] != T[i]: tmp += 1 if tmp % 2 == 0: ans = tmp tmp = 0 for i in range(N): if SS[i] != T[i]: tmp += 1 if tmp % 2 == 1 and tmp < ans: ans = tmp print(ans)