B'You are given a sequence of integers a of length 2n . You have to split these 2n integers into n pairs; each pair will represent the coordinates of a point on a plane. Each number from the sequence a should become the x or y coordinate of exactly one point. Note that some points can be equal. After the points are formed, you have to choose a path s that starts from one of these points, ends at one of these points, and visits all n points at least once. The length of path s is the sum of distances between all adjacent points on the path. In this problem, the distance between two points (x_1, y_1) and (x_2, y_2) is defined as |x_1-x_2| + |y_1-y_2| . Your task is to form n points and choose a path s in such a way that the length of path s is minimized. The first line contains a single integer t ( 1 <= t <= 100 ) -- the number of testcases. The first line of each testcase contains a single integer n ( 2 <= n <= 100 ) -- the number of points to be formed. The next line contains 2n integers a_1, a_2, ... , a_{2n} ( 0 <= a_i <= 1 ,000 ) -- the description of the sequence a . For each testcase, print the minimum possible length of path s in the first line. In the i -th of the following n lines, print two integers x_i and y_i -- the coordinates of the point that needs to be visited at the i -th position. If there are multiple answers, print any of them. In the first testcase, for instance, you can form points (10, 1) and (15, 5) and start the path s from the first point and end it at the second point. Then the length of the path will be |10 - 15| + |1 - 5| = 5 + 4 = 9 . In the second testcase, you can form points (20, 20) , (10, 30) , and (10, 30) , and visit them in that exact order. Then the length of the path will be |20 - 10| + |20 - 30| + |'...