Most crossword puzzle fans are used to anagrams — groups of words with the same letters in different orders — for example OPTS, SPOT, STOP, POTS and POST. Some words however do not have this attribute, no matter how you rearrange their letters, you cannot form another word. Such words are called ananagrams, an example is QUIZ. Obviously such definitions depend on the domain within which we are working; you might think that ATHENE is an ananagram, whereas any chemist would quickly produce ETHANE. One possible domain would be the entire English language, but this could lead to some problems. One could restrict the domain to, say, Music, in which case SCALE becomes a relative ananagram (LACES is not in the same domain) but NOTE is not since it can produce TONE. Write a program that will read in the dictionary of a restricted domain and determine the relative ananagrams. Note that single letter words are, ipso facto, relative ananagrams since they cannot be “rearranged” at all. The dictionary will contain no more than 1000 words.

大多數玩填字遊戲的人對「anagram（變位詞）」應該不陌生，例如這些字：OPTS, SPOT, STOP, POTS and POST。它們都由相同的字母組成，只是順序不同。不過，也有些字是「無法透過任何字母重新排列」而構成其他字的，例如：QUIZ 這種無法變形為其他單字的字叫做 ananagram（非重組詞）。

給定一個有限詞庫中所有單字，請你找出這些單字中哪些字是「relative ananagrams」（相對非重組詞）——也就是在這個詞庫中，沒有其他單字是它的變位詞。