Number by permutation of letters#5142
The permutations of the letters of the string are all distinct strings obtained from it by a permutation of the letters.
Naturally, all permutations of letters can be ordered lexicographically as strings. For example, for the string abba, the list of ordered permutations of letters would look like this: aabb, abab, abba, baab, baba, bbaa.
Find the lexicographic number of the string in the set of all permutations of its letters (numbering starts from zero).
The string , consisting of no more than lowercase Latin letters.
Print the number of the string in the set of permutations of its letters.
Example 1