The God of Parking

Sunyoung often goes shopping along a shopping street that stretches down a long, straight road. She finds parking extremely tedious, so she parks her car anywhere she likes and then walks to the shops she wants to visit.

One day her legs hurt so much that she went to the doctor, who told her to walk as little as possible. But Sunyoung cannot give up shopping. So, putting her special talent to use, she wants to find the best parking spot that minimizes the distance she has to walk.

The road is a single straight line, and every shop is located at an integer coordinate. There is one parking space at every integer coordinate, and it is always free for Sunyoung. She will not move her parked car until she finishes shopping. Sunyoung is very strong, so carrying everything she buys is never a problem, and she must visit every shop she planned to visit. She may park at any integer coordinate.

The first line contains the number of test cases $t$. ($1 \le t \le 100$)

Each test case consists of two lines. The first line contains the number of shops $n$ that Sunyoung will visit ($1 \le n \le 20$), and the second line contains the positions $x_i$ of the $n$ shops, separated by spaces. ($0 \le x_i \le 99$)

For each test case, print on its own line the minimum distance Sunyoung must walk to visit all of her planned shops on foot and return to her parked car.