Sea Sky
Time Limit: 6000/3000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1 Accepted Submission(s): 0
Problem Description
Sea and Sky are the most favorite things of iSea, even when he was a small child.
Suzi once wrote: white dew fly over the river, water and light draw near to the sky. What a wonderful scene it would be, connecting the two charming scenery. But iSea cannot ask help from God, or some other deities in China. The only mean he can use is imagination.
For example, from sea, he can associate with love, from love, he can see sky in (strange logic, aha? leave him alone, we don't really care how he imagine since he is so weird). In this way, he connects "Sea" and "Sky" in mind, fulfills his goal.
However, he can only solve the puzzle with small number of words, when the connection increases, his brain will come to be a total mess. Now, can you smart guys help him?
Now iSea gives you some word pairs he can associate, from any one of them to another. He wishes use the maximum word to make an association list, from ¡°sea¡± to ¡°sky¡±, of course, no word should appear in the list twice because it would lead to an infinite loop. Your task is to find a list, which contains the maximum word and every neighbor word can be connected in mind. If several solutions exist, find the lexicographically minimum one.
Lexicographical sequence is the order in one dictionary. For example, ¡°cat¡± is less than ¡°do¡±, and ¡°do¡± is less than ¡°dog¡±.
Suzi once wrote: white dew fly over the river, water and light draw near to the sky. What a wonderful scene it would be, connecting the two charming scenery. But iSea cannot ask help from God, or some other deities in China. The only mean he can use is imagination.
For example, from sea, he can associate with love, from love, he can see sky in (strange logic, aha? leave him alone, we don't really care how he imagine since he is so weird). In this way, he connects "Sea" and "Sky" in mind, fulfills his goal.
However, he can only solve the puzzle with small number of words, when the connection increases, his brain will come to be a total mess. Now, can you smart guys help him?
Now iSea gives you some word pairs he can associate, from any one of them to another. He wishes use the maximum word to make an association list, from ¡°sea¡± to ¡°sky¡±, of course, no word should appear in the list twice because it would lead to an infinite loop. Your task is to find a list, which contains the maximum word and every neighbor word can be connected in mind. If several solutions exist, find the lexicographically minimum one.
Lexicographical sequence is the order in one dictionary. For example, ¡°cat¡± is less than ¡°do¡±, and ¡°do¡± is less than ¡°dog¡±.
Input
The input file consists of a number of test cases, end by a single zero.
Each test case begins with an integer N (0 < N <= 100), then N lines follow, each line contains two words can connected in mind. You can assume the number of different words and the length of words is no more than sixteen.
Each test case begins with an integer N (0 < N <= 100), then N lines follow, each line contains two words can connected in mind. You can assume the number of different words and the length of words is no more than sixteen.
Output
For each test case, if cannot finish, output ¡°what a pity¡±. Otherwise, output a word sequence with most words, separated by a blank.
Sample Input
2 sea love sky love 7 sea pure pure air air white sky white pure holy holy white sky holy 3 sea blue sky white blue green 0
Sample Output
sea love sky sea pure air white holy sky what a pity
Author
iSea@WHU