2815. Max Pair Sum in an Array - LeetCode

class Solution:
    def maxSum(self, nums: list[int]) -> int:
        ht: dict[int, list[int]] = {}
        result = -1
        for num in nums:
            tmp, max_digit = num, 0
            while tmp:
                tmp, max_digit = tmp // 10, max(max_digit, tmp % 10)
            ht[max_digit] = sorted(ht.get(max_digit, []) + [num])[-2:]
            if len(ht[max_digit]) == 2:
                result = max(result, sum(ht[max_digit]))
        return result