KTV

One song is extremely popular recently, so you and your friends decided to sing it in KTV. The song has 3 characters, so exactly 3 people should sing together each time (yes, there are 3 micro- phones in the room). There are exactly 9 people, so you decided that each person sings exactly once. In other words, all the peo- ple are divided into 3 disjoint groups, so that every person is in exactly one group. However, some people don’t want to sing with some other peo- ple, and some combinations perform worse than others combina- tions. Given a score for every possible combination of 3 people, what is the largest possible score for all the 3 groups? Input The input consists of at most 1000 test cases. Each case begins with a line containing a single integer n (0 < n < 81), the number of possible combinations. The next n lines each contains 4 positive integers a, b, c, s (1 ≤ a < b < c ≤ 9, 0 < s < 10000), that means a score of s is given to the combination (a, b, c). The last case is followed by a single zero, which should not be processed. Output For each test case, print the case number and the largest score. If it is impossible, print ‘-1’. Sample Input 3 1231 4562 7893 4 1231 1452 1673 1894 0 Sample Output Case 1: 6 Case 2: -1