You are given a string `s` that contains digits `0-9`, addition symbols `'+'`, and multiplication symbols `'*'` only, representing a valid math expression of single digit numbers (e.g., `3+5*2`). This expression was given to `n` elementary school students. The students were instructed to get the answer of the expression by following this order of operations:

1. Compute multiplication, reading from left to right; Then,
2. Compute addition, reading from left to right.

You are given an integer array `answers` of length `n`, which are the submitted answers of the students in no particular order. You are asked to grade the `answers`, by following these rules:

- If an answer equals the correct answer of the expression, this student will be rewarded `5` points;
- Otherwise, if the answer could be interpreted as if the student applied the operators in the wrong order but had correct arithmetic, this student will be rewarded `2` points;
- Otherwise, this student will be rewarded `0` points.

Return the sum of the points of the students.

Example 1:

    Input: s = "7+3*1*2", answers = [20,13,42]
    Output: 7
    Explanation: As illustrated above, the correct answer of the expression is 13, therefore one student is rewarded 5 points: [20,13,42]
    A student might have applied the operators in this wrong order: ((7+3)*1)*2 = 20. Therefore one student is rewarded 2 points: [20,13,42]
    The points for the students are: [2,5,0]. The sum of the points is 2+5+0=7.

Example 2:

    Input: s = "3+5*2", answers = [13,0,10,13,13,16,16]
    Output: 19
    Explanation: The correct answer of the expression is 13, therefore three students are rewarded 5 points each: [13,0,10,13,13,16,16]
    A student might have applied the operators in this wrong order: ((3+5)*2 = 16. Therefore two students are rewarded 2 points: [13,0,10,13,13,16,16]
    The points for the students are: [5,0,0,5,5,2,2]. The sum of the points is 5+0+0+5+5+2+2=19.

Example 3:

    Input: s = "6+0*1", answers = [12,9,6,4,8,6]
    Output: 10
    Explanation: The correct answer of the expression is 6.
    If a student had incorrectly done (6+0)*1, the answer would also be 6.
    By the rules of grading, the students will still be rewarded 5 points (as they got the correct answer), not 2 points.
    The points for the students are: [0,0,5,0,0,5]. The sum of the points is 10.

Constraints:

- `3 <= s.length <= 31`
- `s` represents a valid expression that contains only digits `0-9`, `'+'`, and `'*'` only.
- All the integer operands in the expression are in the inclusive range `[0, 9]`.
- `1 <=` The count of all operators (`'+'` and `'*'`) in the math expression `<= 15`
- Test data are generated such that the correct answer of the expression is in the range of `[0, 1000]`.
- `n == answers.length`
- `1 <= n <= 104`
- `0 <= answers[i] <= 1000`