def count_affected_swaps(N, A, B):
    # 将输入的二进制字符串转换为列表
    A = list(A)
    B = list(B)
    
    # 计算原始的或结果
    original_or = [str(int(a) | int(b)) for a, b in zip(A, B)]
    
    count = 0
    
    # 遍历所有可能的交换对
    for i in range(N):
        for j in range(i + 1, N):
            # 交换A中的第i位和第j位
            A[i], A[j] = A[j], A[i]
            # 计算新的或结果
            new_or = [str(int(a) | int(b)) for a, b in zip(A, B)]
            # 如果或结果发生变化，则计数
            if new_or != original_or:
                count += 1
            # 恢复交换
            A[i], A[j] = A[j], A[i]
    
    return count

# 读取输入
N = int(input())
A = input().strip()
B = input().strip()

# 计算并输出结果
print(count_affected_swaps(N, A, B))