## Problem F: Ultra-QuickSort

In this problem, you have to analyze a particular sorting algorithm.
The algorithm processes a sequence of *n* distinct integers by swapping
two adjacent sequence elements until the sequence is sorted in ascending order.
For the input sequence
`9 1 0 5 4` ,

Ultra-QuickSort produces the output
`0 1 4 5 9` .

Your task is to determine how many swap operations Ultra-QuickSort needs to
perform in order to sort a given input sequence.
The input contains several test cases. Every test case begins with a line
that contains a single integer *n < 500,000* -- the length of the input sequence.
Each of the the following *n* lines contains a single integer
*0 ≤ a[i] ≤ 999,999,999*, the *i*-th input sequence element. Input is terminated
by a sequence of length *n = 0*. This sequence must not be processed.

For every input sequence, your program prints a single line containing an
integer number *op*, the minimum number of swap operations necessary
to sort the given input sequence.

### Sample Input

5
9
1
0
5
4
3
1
2
3
0

### Output for Sample Input

6
0

*Stefan Büttcher*