class Solution:

    def __init__(self, nums: List[int]):
        self.nums = nums

    def pick(self, target: int) -> int:

        count = 0
        res = -1

        for idx, ele in enumerate(self.nums):
            if ele == target:
                count += 1

                if count == 1:
                    res = idx
                else:
                    rand = randint(1, count)
                    if rand == 1:
                        res = idx

        return res