def min_operations(N, S, T):
    S = list(S)
    T = list(T)
    operations = 0
    flip = 0

    for i in range(N-1, -1, -1):
        if (S[i] == T[i] and flip % 2 == 0) or (S[i] != T[i] and flip % 2 == 1):
            continue
        else:
            flip += 1
            operations += 1

    return operations


N = int(input().strip())
S = input().strip()
T = input().strip()

print(min_operations(N, S, T))