371. Sum of Two Integers - LeetCode

class Solution1:
    def getSum(self, a: int, b: int) -> int:
        MASK, xor, carry = 1023, a ^ b, (a & b) << 1
        if carry & MASK:
            return self.getSum(xor, carry)
        return xor & MASK if carry else xor


class Solution:
    def getSum(self, a: int, b: int) -> int:
        MASK = 1023
        while b & MASK:
            a, b = a ^ b, (a & b) << 1
        return a & MASK if b else a