www

int hanoi(int n)
{
    if(n == 1)
    return 1;
    else
    {
        return 2 * hanoi(n - 1) + 1;
    }
}
int main()
{
    int num = 0;
    scanf("%d", &num);
    printf("%d个盘子需要移动%d次\n",num ,hanoi(num));
    return 0;
}