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class Solution:
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    from collections import defaultdict
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    def isPossible(self, nums):
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        # If the length of the array is less than 3, it's not possible to create subsequences of length 3 or more.
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        if len(nums) < 3:
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            return False
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        # 'count' dictionary stores the frequency of each number in the input array.
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        count = defaultdict(int)
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        # 'tails' dictionary stores the number of subsequences that end at a certain number.
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        tails = defaultdict(int)
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        # Populate the 'count' dictionary with the frequency of each number.
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        for num in nums:
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            count[num] += 1
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        # Iterate through the input array.
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        for num in nums:
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            # If the count of the current number is 0, it means this number has already been used in a subsequence.
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            if count[num] == 0:
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                continue
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            # If there is a subsequence that ends with the current number minus 1,
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            # it means we can extend that subsequence by adding the current number.
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            elif tails[num - 1] > 0:
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                tails[
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                    num - 1
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                ] -= 1  # Decrease the count of the tails that end with the current number minus 1.
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                tails[
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                    num
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                ] += 1  # Increase the count of the tails that end with the current number.
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            # If there are enough numbers after the current number to form a subsequence,
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            # create a new subsequence starting with the current number.
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            elif count[num + 1] > 0 and count[num + 2] > 0:
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                count[num + 1] -= 1  # Decrease the count of the next number.
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                count[
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                    num + 2
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                ] -= 1  # Decrease the count of the number after the next number.
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                tails[
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                    num + 2
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                ] += 1  # Increase the count of the tails that end with the number after the next number.
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            else:
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                # If we can't extend an existing subsequence or start a new one, return False.
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                return False
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            # Decrease the count of the current number since it's used in a subsequence.
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            count[num] -= 1
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        # If the function successfully iterates through the entire array, return True.
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        return True