class Solution:    def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:        if len(hand) % groupSize != 0:            return False        counts = Counter(hand)        groups = 0        for num in hand:            i = 0            while i < groupSize and counts[num + i]:                i += 1            if i == groupSize:                groups += 1                for new_num in range(num, num + i):                    counts[new_num] -= 1        return groups == len(hand)//groupSize