Leetcode-Easy 984. String Without AAA or BBB

Input: A = 1, B = 2
Output: "abb"
Explanation: "abb", "bab" and "bba" are all correct answers.

Example 2:

Input: A = 4, B = 1
Output: "aabaa"

class Solution(object):
    def strWithout3a3b(self, A, B):
        ans = []

        while A or B:
            if len(ans) >= 2 and ans[-1] == ans[-2]:
                writeA = ans[-1] == 'b'
            else:
                writeA = A >= B

            if writeA:
                A -= 1
                ans.append('a')
            else:
                B -= 1
                ans.append('b')

        return "".join(ans)