The sadists who design problems for ACM programming contests often like to include the abbre-viation "ACM" somewhere in their problem descriptions. Thus, in years past, the World Finals has had problems involving "Apartment Construction Management," the "Atheneum of Culture and Movies," the "Association of Cover Manufacturers," "ACM Airlines," the "Association for Computa- tional Marinelife," and even an insect named "Amelia Cheese Mite." However, the number of word combinations beginning with A, C, and M that make sense is finite and the problem writers are starting to run out of ideas (it's hard to think of problems about "Antidisestablishmentarianistic Chthonian Metalinguistics"). Fortunately, modern culture allows more flexibility in designing abbreviations -- consider, for example:
GDB -- Gnu DeBugger
LINUX -- either "LINus's UniX" or "LINUs's miniX" or "Linux Is Not UniX"
SNOBOL -- StriNg Oriented symBOlic Language
SPITBOL -- SPeedy ImplemenTation of snoBOL
The rules used in these examples seem to be:
The input file consists of multiple scenarios. Each scenario begins with an integer 100 >= n >= 1 followed by n insignificant words, all in lower case, one per line with no extra white space. (A line containing 0 indicates end of input.) Following this are one or more test cases for this scenario, one per line, followed by a line containing the phrase "LAST CASE". Each line containing a test case begins with an abbreviation (uppercase letters only) followed by a phrase (lowercase letters and spaces only). The abbreviation has length at least 1 and the phrase contains at least one significant word. No input line (including abbreviation, phrase, and spaces) will contain more than 150 characters. Within these limits, however, abbreviations and phrase words may be any length.
For each test case, output the abbreviation followed by either
is not a valid abbreviation
or
can be formed in i ways
where i is the number of different ways in which the letters of the abbreviation may be assigned to the letters in the phrase according to the rules above. The value of i will not exceed the range of a 32-bit signed integer.
2 and of ACM academy of computer makers RADAR radio detection and ranging LAST CASE 2 a an APPLY an apple a day LAST CASE 0
ACM can be formed in 2 ways RADAR is not a valid abbreviation APPLY can be formed in 1 ways