import pyutil as pyu
pyu.get_local_pyinfo()

print(pyu.ps2("python-dotenv"))

from typing import List

class Solution:
  def singleNumber(self, nums: List[int]) -> int:
    ones = 0
    twos = 0

    for num in nums:
      ones ^= num & ~twos
      twos ^= num & ~ones

    return ones

new Solution().singleNumber()