# 1822. Hanoi Tower IV

A double tower of hanoi contains 2n disks of n different sizes,two of each size.As usual,we’re required to move only one disk at a time,without putting a larger one over a smaller one.

What if we are required to reproduce the original top-to-bottom order of all the equal-size disks in the final arrangement?

### 输入格式

There are so many tests.Each test have one interger n(1<=n<=60) represented the number of disks.

### 输出格式

Output a single number of the minimum steps in a line.

### 样例

Input
1
5

Output
3
123


37 人解决，78 人已尝试。

52 份提交通过，共有 128 份提交。

5.2 EMB 奖励。