Bob has been assigned \(N\) tasks arranged in a row, and in one day, he can perform one task. So, to perform all of the \(N\) tasks, he will take \(N\) days.

He has been given an array \(A\) containing \(N\) integers where \(A[i] = X\) denotes that on the \(i^{th}\) day he has to perform the \(X^{th}\) task.

Bob has been given an integer \(K\) and has to tell the minimum days he will take to reach the configuration where there are exactly \(K\) tasks between a pair of completed tasks, and all these \(K\) tasks are not completed.

Help Bob to find the minimum days to reach the configuration mentioned above or print \(-1\) if it's impossible.

Input Format:

The first line contains a single integer \(T\), denoting the number of test cases.
The first line of each test case contains two spaced integers, \(N\) and \(K\).
The second line of each test case contains \(N\) space-separated integers, denoting the elements of the array \(A\).

Output Format:

For each test case, print the minimum days to reach the configuration mentioned in the problem statement. Print \(-1\) if it's impossible.

Constraints:

\(1 <= T <= 10\)

\(1 <= N <= 10^5\)

\(1 <= A[i] <= N\)

\(0 <= K <= 10^5\)