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# Description

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.

# Input

The input contains several test cases. Every test case begins with a line that contains a single integer $$n < 5\times10^5$$ : the length of the input sequence. Each of the the following $$n$$ lines contains a single integer $$0 \le a_i < 10^9$$, the i-th input sequence element. Input is terminated by a sequence of length $$n = 0$$. This sequence must not be processed.

# Output

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.

# Samples

## Sample #1

### Input

5
9 1 0 5 4
3
1 2 3
0


### Output

6
0


ID
1020

9

(无)

(无)

9

4

44%