Medium

32.9%

Given root of binary search tree and K as input, find K-th smallest element in BST. Your task is to return the K-th smallest element in BST from the function **k_smallest_element().**

**Note:** The Time Complexity will be O(h) where h is the height of the Tree.

**Input:**

The first line of input will contain the number of test cases T. Then T test cases follow. First line of every test case will be n, denoting the number of nodes in the BST. Second line of every test case will be n spaced integers denoting the Integer value of Nodes in BST. Third line of every test case will be k, denoting kth the smallest number.

**Output:**

For each test case, output will be the kth smallest element of BST.

**Constraints:**

1<=T<=100

1<=N<=100

1<=K<=N

**Example(To be used only for expected output):
Input:**

1

5

20 8 4 22 12

3

12