Given a list of `words`, list of single `letters` (might be repeating) and `score` of every character.

Return the maximum score of any valid set of words formed by using the given letters (`words[i]` cannot be used two or more times).

It is not necessary to use all characters in `letters` and each letter can only be used once. Score of letters `'a'`, `'b'`, `'c'`, ... ,`'z'` is given by `score[0]`, `score[1]`, ... , `score[25]` respectively.

Example 1:

    Input: words = ["dog","cat","dad","good"], letters = ["a","a","c","d","d","d","g","o","o"], score = [1,0,9,5,0,0,3,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0]
    Output: 23
    Explanation:
    Score  a=1, c=9, d=5, g=3, o=2
    Given letters, we can form the words "dad" (5+1+5) and "good" (3+2+2+5) with a score of 23.
    Words "dad" and "dog" only get a score of 21.

Example 2:

    Input: words = ["xxxz","ax","bx","cx"], letters = ["z","a","b","c","x","x","x"], score = [4,4,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,5,0,10]
    Output: 27
    Explanation:
    Score  a=4, b=4, c=4, x=5, z=10
    Given letters, we can form the words "ax" (4+5), "bx" (4+5) and "cx" (4+5) with a score of 27.
    Word "xxxz" only get a score of 25.

Example 3:

    Input: words = ["leetcode"], letters = ["l","e","t","c","o","d"], score = [0,0,1,1,1,0,0,0,0,0,0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0]
    Output: 0
    Explanation:
    Letter "e" can only be used once.

Constraints:

- `1 <= words.length <= 14`
- `1 <= words[i].length <= 15`
- `1 <= letters.length <= 100`
- `letters[i].length == 1`
- `score.length == 26`
- `0 <= score[i] <= 10`
- `words[i]`, `letters[i]` contains only lower case English letters.