Given an array arr of positive integers sorted in a strictly increasing order, and an integer k.
Find the kth positive integer that is missing from this array.
Example 1:
Input: arr = [2,3,4,7,11], k = 5
Output: 9
Explanation: The missing positive integers are [1,5,6,8,9,10,12,13,...]. The 5th missing positive integer is 9.
Example 2:
Input: arr = [1,2,3,4], k = 2
Output: 6
Explanation: The missing positive integers are [5,6,7,...]. The 2nd missing positive integer is 6.
Constraints:
1 <= arr.length <= 1000
1 <= arr[i] <= 1000
1 <= k <= 1000
arr[i] < arr[j] for 1 <= i < j <= arr.length
class Solution:
    def findKthPositive(self, arr: List[int], k: int) -> int:
        n_miss = 0
        i = 0
        c = 1
        n = len(arr)
        while n_miss < k:
            if i < n and arr[i] == c:
                c += 1
                i += 1
            else:
                c += 1
                n_miss += 1
        return c - 1
class Solution:
    def findKthPositive(self, arr: List[int], k: int) -> int:
        n_miss = 0
        i = 0
        c = 1
        n = len(arr)
        while n_miss < k:
            if i < n and arr[i] == c:
                c += 1
                i += 1
            else:
                c += 1
                n_miss += 1
        return c - 1