write a go solution for Description:
Madeline has an array a of n integers. A pair (u,v) of integers forms an inversion in a if:

- 1<=u<v<=n.
- a_u>a_v.

Madeline recently found a magical paper, which allows her to write two indices u and v and swap the values a_u and a_v. Being bored, she decided to write a list of pairs (u_i,v_i) with the following conditions:

- all the pairs in the list are distinct and form an inversion in a.
- all the pairs that form an inversion in a are in the list.
- Starting from the given array, if you swap the values at indices u_1 and v_1, then the values at indices u_2 and v_2 and so on, then after all pairs are processed, the array a will be sorted in non-decreasing order.

Construct such a list or determine that no such list exists. If there are multiple possible answers, you may find any of them.

Input Format:
The first line of the input contains a single integer n (1<=n<=1000) — the length of the array.

Next line contains n integers a_1,a_2,...,a_n (1<=a_i<=10^9)  — elements of the array.

Output Format:
Print -1 if no such list exists. Otherwise in the first line you should print a single integer m (0<=m<=dfracn(n-1)2) — number of pairs in the list.

The i-th of the following m lines should contain two integers u_i,v_i (1<=u_i<v_i<=n).

If there are multiple possible answers, you may find any of them.

Note:
In the first sample test case the array will change in this order [3,1,2]arrow[2,1,3]arrow[1,2,3].

In the second sample test case it will be [1,8,1,6]arrow[1,6,1,8]arrow[1,1,6,8].

In the third sample test case the array is already sorted.. Output only the code with no comments, explanation, or additional text.