原题来自：ACM Pacific NW Region 1998
输入数据为多组数据，每组数据读到 999 时结束。
对于每组数据，如果不存在一个数字串是另一个串的前缀，输出一行Set t is immediately decodable，否则输出一行Set t is not immediately decodable，其中 ttt 是这一组数据的组号。
Set 1 is immediately decodable
Set 2 is not immediately decodable
An encoding of a set of symbols is said to be immediately decodable if no code for one symbol is the prefix of a code for another symbol. We will assume for this problem that all codes are in binary, that no two codes within a set of codes are the same, that each code has at least one bit and no more than ten bits, and that each set has at least two codes and no more than eight.
数字串只包含 0,10,10,1，记每个数字串长度为 lll，则 1≤l≤101\le l\le 101≤l≤10。每组数据至少有 222 个数字串，至多有 888 个数字串。