Given a string, count all distinct subsequences (not substrings).
As defined previously, a subsequence is a collection of characters from the string (they don't have to be contiguous).
For example, for the string
aba, there are 6 distinct subsequences: (
The string, on one line. It will consist only of lowercase letters.
It will be no longer than characters long (this is easier than all substrings!).
The number of distinct subsequences.
Note that this number may be ridiculously large, so print it .