B. Points and Minimum Distancetime limit per test2 secondsmemory limit per test512 megabytesinputstandard inputoutputstandard outputYou 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.InputThe first line contains a single integer t (1 \le t \le 100) — the number of testcases.The first line of each testcase contains a single integer n (2 \le n \le 100) — the number of points to be formed.The next line contains 2n integers a_1, a_2, \dots, a_{2n} (0 \le a_i \le 1\,000) — the description of the sequence a.OutputFor 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.ExampleInput
2215 1 10 5310 30 20 20 30 10Output
9
10 1
15 5
20
20 20
10 30
10 30
NoteIn 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| + |10 - 10| + |30 - 30| = 10 + 10 + 0 + 0 = 20.
2215 1 10 5310 30 20 20 30 10
9 10 1 15 5 20 20 20 10 30 10 30 
['greedy', 'math', 'sortings', '*800']