Substitution Cipher |
Antique Comedians of Malidinesia would like to play a new discovered comedy of Aristofanes. Putting it on a stage should be a big surprise for the audience so all the preparations must be kept absolutely secret. The ACM director suspects one of his competitors of reading his correspondece. To prevent other companies from revealing his secret, he decided to use a substitution cipher in all the letters mentioning the new play.
Substitution cipher is defined by a substitution table assigning each
character of the substitution alphabet another character of the same alphabet.
The assignment is a bijection (to each character exactly one character is
assigned - not neccessary different). The director is afraid of disclosing the
substitution table and therefore he changes it frequently. After each change he
chooses a few words from a dictionary by random, encrypts them and sends them
together with an encrypted message. The plain (i.e. non-encrypted) words are
sent by a secure channel, not by mail. The recipient of the message can then
compare plain and encrypted words and create a new substitution table.
Unfortunately, one of the ACM cipher specialists have found that this
system is sometimes insecure. Some messages can be decrypted by the rival
company even without knowing the plain words. The reason is that when the
director chooses the words from the dictionary and encrypts them, he never
changes their order (the words in the dictionary are lexicographically sorted).
String is lexicografically smaller than
if there exists an integer i,
, such that
aj=bj for each j,
and ai
< bi.
The director is interested in which of his messages could be read by the
rival company. You are to write a program to determine that.
The input consists of N cases. The first line of the input contains
only positive integer N. Then follow the cases. The first line of each
case contains only two positive integers A, , and K, separated by
space. A determines the size of the substitution alphabet (the
substitution alphabet consists of the first A lowercase letters of the
english alphabet (a-z) and K is the number of encrypted
words. The plain words contain only the letters of the substitution alphabet.
The plain message can contain any symbol, but only the letters of the
substitution alphabet are encrypted. Then follow K lines, each containing
exactly one encrypted word. At the next line is encrypted message.
For each case, print exactly one line. If it is possible to decrypt the message uniquely, print the decrypted message. Otherwise, print the sentence `Message cannot be decrypted.'.
2 5 6 cebdbac cac ecd dca aba bac cedab 4 4 cca cad aac bca bdac
abcde Message cannot be decrypted.