File Retrieval |
The operating system of your computer indexes the files on your hard disk based on their contents, and provides textual search over them. The content of each file is a non-empty string of lowercase letters. To do a search, you specify a key, which is also a non-empty string of lowercase letters. The result is a list of all the files that contain the key as a substring. A string s is a substring of a string t if t contains all characters of s as a contiguous sequence. For instance, ``foofoo", ``cafoo", ``foota" and ``foo" all contain ``foo" as a substring, while ``foa", ``fofo", ``fioo" and ``oofo" do not.
You know the content of each file on your hard disk, and wonder whether each subset of the files is searchable. A subset of the files is searchable if there exists at least one key that produces exactly the list of those files as a result. Given the contents of the files on your hard disk, you are asked to compute the number of non-empty searchable subsets.
The last test case is followed by a line containing one zero.
For each test case output a line with an integer representing the number of non-empty searchable subsets.
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