Associated Course(s):
Interview Preparation

You are given an array **A** of size **N**. You need to find **all pairs** in the array that sum to a number **K**. If no such pair exists then output will be **-1**. The elements of the array are **distinct **and are in **sorted **order.

**Note:** (a,b) and (b,a) are considered same. Also, an element cannot pair with itself, i.e., (a,a) is invalid.

**Input:**

The first line of input is **T** denoting the number of testcase. **T** testcases follow. Each testcase contains **three **lines of input. The first line is the size of array N. The second line contains N elements separated by spaces. The third line contains the sum K.

**Output:**

For each testcase, print all the pairs such that there sum is equal to K.

**Constraints:**

1 <= T <= 100

0 <= A_{i} <=10^{7}

2 <= N <= 10^{7}

0 <= K <= 10^{7}

**Examples:**

**Input:**

2

7

1 2 3 4 5 6 7

98

7

1 2 3 4 5 6 7

8

**Output:**

-1

1 7 8

2 6 8

3 5 8

**Explanation:
Testcase1: **We cannot find any pair that sums to 98

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