Problems

# Bubble sort

# Bubble sort

Determine how many exchange operations are done in bubble sort algorithm to sort the elements of array in ascending order.

#### Input

The first line contains the number of elements **n** (**1** ≤ **n** ≤ **1000**) in array. The second line contains the array itself. It is guaranteed that all array elements are different and do not exceed `10`

by absolute value.^{9}

#### Output

Print the number of swaps in bubble sort.

Input example #1

3 1 3 2

Output example #1

1

Input example #2

2 2 1

Output example #2

1

Input example #3

4 4 1 5 3

Output example #3

3