write a go solution for Description:
Consider a sequence of integers a_1,a_2,ldots,a_n. In one move, you can select any element of the sequence and delete it. After an element is deleted, all elements to the right are shifted to the left by 1 position, so there are no empty spaces in the sequence. So after you make a move, the sequence's length decreases by 1. The indices of the elements after the move are recalculated.

E. g. let the sequence be a=[3,2,2,1,5]. Let's select the element a_3=2 in a move. Then after the move the sequence will be equal to a=[3,2,1,5], so the 3-rd element of the new sequence will be a_3=1 and the 4-th element will be a_4=5.

You are given a sequence a_1,a_2,ldots,a_n and a number k. You need to find the minimum number of moves you have to make so that in the resulting sequence there will be at least k elements that are equal to their indices, i. e. the resulting sequence b_1,b_2,ldots,b_m will contain at least k indices i such that b_i=i.

Input Format:
The first line contains one integer t (1<=t<=100) — the number of test cases. Then t test cases follow.

Each test case consists of two consecutive lines. The first line contains two integers n and k (1<=k<=n<=2000). The second line contains a sequence of integers a_1,a_2,ldots,a_n (1<=a_i<=n). The numbers in the sequence are not necessarily different.

It is guaranteed that the sum of n over all test cases doesn't exceed 2000.

Output Format:
For each test case output in a single line:

- -1 if there's no desired move sequence;
- otherwise, the integer x (0<=x<=n) — the minimum number of the moves to be made so that the resulting sequence will contain at least k elements that are equal to their indices.

Note:
In the first test case the sequence doesn't satisfy the desired condition, but it can be provided by deleting the first element, hence the sequence will be [1,2,3,4,5,6] and 6 elements will be equal to their indices.

In the second test case there are two ways to get the desired result in 2 moves: the first one is to delete the 1-st and the 3-rd elements so that the sequence will be [1,2,3] and have 3 elements equal to their indices; the second way is to delete the 2-nd and the 3-rd elements to get the sequence [5,2,3] with 2 desired elements.. Output only the code with no comments, explanation, or additional text.