Time Limit: 1 s
Memory Limit: 128 MB

Submission：15
AC：7
Score：99.64

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.

input

5
9
1
0
5
4
3
1
2
3
0

output

6
0