Given 2 sorted arrays A and B of size N each. Print sum of middle elements of the array obtained after merging the given arrays.

Input:
The first line contains T denoting the number of testcases. Then follows description of testcases.
Each case begins with a single positive integer N denoting the size of array. The second line contains the N space separated positive integers denoting the elements of array A. The third line contains N space separated positive integers denoting the elements of array B.

Output:
For each testcase, print the sum of middle elements of two sorted arrays. The number of the elements in the merged array are even so there will be 2 numbers in the center n/2 and n/2 +1. You have to print their sum.