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}