You are given a **0-indexed** 2D integer array `questions` where `questions[i] = [pointsi, brainpoweri]`.

The array describes the questions of an exam, where you have to process the questions **in order** (i.e., starting from question `0`) and make a decision whether to **solve** or **skip** each question. Solving question `i` will **earn** you `pointsi` points but you will be **unable** to solve each of the next `brainpoweri` questions. If you skip question `i`, you get to make the decision on the next question.

*   For example, given `questions = [[3, 2], [4, 3], [4, 4], [2, 5]]`:
    *   If question `0` is solved, you will earn `3` points but you will be unable to solve questions `1` and `2`.
    *   If instead, question `0` is skipped and question `1` is solved, you will earn `4` points but you will be unable to solve questions `2` and `3`.

Return _the **maximum** points you can earn for the exam_.

**Example 1:**

**Input:** questions = \[\[3,2\],\[4,3\],\[4,4\],\[2,5\]\]
**Output:** 5
**Explanation:** The maximum points can be earned by solving questions 0 and 3.
- Solve question 0: Earn 3 points, will be unable to solve the next 2 questions
- Unable to solve questions 1 and 2
- Solve question 3: Earn 2 points
Total points earned: 3 + 2 = 5. There is no other way to earn 5 or more points.

**Example 2:**

**Input:** questions = \[\[1,1\],\[2,2\],\[3,3\],\[4,4\],\[5,5\]\]
**Output:** 7
**Explanation:** The maximum points can be earned by solving questions 1 and 4.
- Skip question 0
- Solve question 1: Earn 2 points, will be unable to solve the next 2 questions
- Unable to solve questions 2 and 3
- Solve question 4: Earn 5 points
Total points earned: 2 + 5 = 7. There is no other way to earn 7 or more points.

**Constraints:**

*   `1 <= questions.length <= 105`
*   `questions[i].length == 2`
*   `1 <= pointsi, brainpoweri <= 105`


def longest_subsequence_repeated_k(s, k):
    counts = [0] * 26
    for c in s:
        counts[ord(c) - ord('a')] += 1
    seq = ''.join([chr(i + ord('a')) * (counts[i] // k) for i in range(25, -1, -1)])
    return seq
