# 10005 - All Falls Down

Cause when it all falls down, then whatever
When it don't work out for the better
If we just ain't right, and it's time to say goodbye
When it all falls down, when it all falls down
I'll be fine
I'll be fine
You're the drug that I'm addicted to and I want you so bad
But I'll be fine

——Alan Walker 《All Falls Down》

wlxsq感觉很神奇，于是想把它们加起来。

### 样例

#### 输入

3

#### 输出

44

### 提示

n=3时，表达式为1\times 2+3\times 4+5\times 6=44

 时间限制 1 秒 内存限制 128 MB