class Solution:
    def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:
        if not len(hand) % groupSize == 0:
            return False

        counter = Counter(hand)
        # print(counter.items())
        for key in sorted(counter.keys()):
            if counter[key] == 0:
                continue
            if counter[key] > 0:
                num_of_cards = counter[key]
                for delta_i in range(groupSize):
                    # print(key + delta_i)
                    counter[key + delta_i] -= num_of_cards
                    if counter[key + delta_i] < 0:
                        return False

        return True