from typing import List, Optional


class Solution:
    def twoSum(self, nums: List[int], target: int) -> Optional[List[int]]:
        for first_index, first_number in enumerate(nums):
            for second_index, second_number in enumerate(nums):
                if first_index == second_index:
                    pass
                elif first_number + second_number == target:
                    return [first_index, second_index]
                else:
                    continue