A step array is an array of integer where each element has a difference of at most k with its neighbor. Given a key x, we need to find the index value of k if multiple elements exist, return the first occurrence of the key.

**Input:**

The first line of the input contains an integer **T**, the number of test cases. For each test case, the first line contains two integer **n & k** denoting the size of array **arr** and the maximum difference between adjacent elements respectively. Next line contains** n** space separated integers denoting the elements of the array **arr**** **with at most **k** difference between adjacent elements. Next line contains an integer **x **which is to be found in the array **arr**.

**Output:**

For each test case, the output is an integer displaying the index of the element **x **in the array arr. If the element is not present in the array return **-1**.

**Constraints:**

1<=T<=100

1<=n<=50

1<=k<=30

1<=x<=1000

**Example:
Input:**

2

5 1

4 5 6 7 6

6

6 20

20 40 50 70 70 60

60

2

5

**Explanation:
1. **The first index of 6 is 2.

Author: Vanshika_pec

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