Alice has N boxes, and each box has certain non zero number of chocolates. These boxes are numbered from 1 to N.

Alice is planning to go to wonderland. She wants to carry exactly K number of chocolates and she can carry only 2 boxes. So she wants to know the number of ways in which she can select 2 boxes such that total number of chocolates in them is K.

Input
First line of the input is the number of test cases T. It is followed by T test cases. Each test case has 3 lines. First line is the number of boxes N and the next line has N space separated integers where the i^th integer is the number of chocolates in the i^th box and 3rd line of each test case contains value of K.

Output
For each test case, output a single number, the number of ways in which she can select the boxes.

Constraints

1<=T(number of test cases)<=10

1<=N<=10^5

1<=Number of Chocolates in i^th box<=100