The input file contains several sets of inputs. The total number of sets will be less than

**50**. The description of each set is given below:Each set starts with one integer

**N (4 ≤ N ≤ 40)**which indicates the total number of jaguar warriors. You can assume that**N**is multiple of**4**. The next line will contain**N**numbers which indicates the final formation of the jaguars. Consecutive numbers will be separated by a single space.The input will be terminated by the set where

**N = 0**. And this set should not be processed.