Herding Frosh

One day, a lawn in the centre of campus became infested with Frosh. In an effort to beautify the campus, one of our illustrious senior classmen decided to round them up using a length of pink silk. Your job is to compute how much silk was required to complete the task. The senior classman tied the silk to a telephone post, and walked around the perimeter of the area containing the Frosh, drawing the silk taught so as to encircle all of them. He then returned to the telephone post. The senior classman used the minimum amount of silk necessary to encircle all the frosh plus one extra metre at each end to tie it. You may assume that the telephone post is at coordinates (0,0), where the first dimension is North/South and the second dimension is East/West. The coordinates of the Frosh are given in metres relative to the post. There are no more than 1000 Frosh. Input The input begins with a single positive integer on a line by itself indicating the number of the cases following, each of them as described below. This line is followed by a blank line, and there is also a blank line between two consecutive inputs. The input consists of a line specifying the number of Frosh, followed by one line per Frosh with two real numbers his or her position. Output For each test case, the output must follow the description below. The outputs of two consecutive cases will be separated by a blank line. The output consists of a single number - the length of silk in metres, to two decimal places. Sample Input 1 4 1.0 1.0 -1.0 1.0 -1.0 -1.0 1.0 -1.0 Sample Output 10.83