You have been given the job of forming the quiz teams for the next ‘MCA CPCI Quiz Championship’. There are 2 ∗ N students interested to participate and you have to form N teams, each team consisting of two members. Since the members have to practice together, all the students want their members house as near as possible. Let x1 be the distance between the houses of group 1, x2 be the distance between the houses of group 2 and so on. You have to make sure the summation (x1 +x2 +x3 +. . .+xn) is minimized. Input There will be many cases in the input file. Each case starts with an integer N (N ≤ 8). The next 2 ∗ N lines will given the information of the students. Each line starts with the students name, followed by the x coordinate and then the y coordinate. Both x,y are integers in the range 0 to 1000. Students name will consist of lowercase letters only and the length will be at most 20. Input is terminated by a case where N is equal to 0. Output For each case, output the case number followed by the summation of the distances, rounded to 2 decimal places. Follow the sample for exact format. Sample Input 5 sohel 10 10 mahmud 20 10 sanny 5 5 prince 1 1 per 120 3 mf 6 6 kugel 50 60 joey 3 24 limon 6 9 manzoor 0 0 1 derek 9 9 jimmy 10 10 0 Sample Output Case 1: 118.40 Case 2: 1.41