# 上海高校程序设计邀请赛（华东理工大学专场）

G. Sort

You want to process a sequence of $n$ distinct integers by swapping two adjacent sequence elements until the sequence is sorted in ascending order.

### 输入格式

There are several test cases, please process till EOF.

For each test case, the first line contains integer $n$ $(1 \leq n \leq 10^5)$. The second line contains $n$ space-separated integers $a_1, a_2, \ldots, a_n$ $(1 \leq a_i \leq 10^9)$.

### 输出格式

For each test case, output the minimum times of swapping in one line.

### 样例

Input
2
1 2

Output
0


NaN