[Python], simple, beats 98%
\nclass Solution(object):\n    def strWithout3a3b(self, A, B):\n        """\n        :type A: int\n        :type B: int\n        :rtype: str\n        """\n     
```\nclass Solution(object):\n    def strWithout3a3b(self, A, B):\n        """\n        :type A: int\n        :type B: int\n        :rtype: str\n        """\n        res = ""\n        curr = \'a\' if A>B else \'b\'\n        while A>0 or B>0:\n            if curr == \'a\':\n                if A>B and A>1:\n                    res += "aa"\n                    A -= 2\n                else: \n                    res+= "a"\n                    A -= 1\n                curr = "b"\n            else:\n                if B>A and B>1:\n                    res += "bb"\n                    B -= 2\n                else: \n                    res+= "b"\n                    B -= 1\n                curr = "a"\n                \n        return res\n```
[]