'''

Given two binary strings a and b, return their sum as a binary string.



Example 1:

Input: a = "11", b = "1"
Output: "100"
Example 2:

Input: a = "1010", b = "1011"
Output: "10101"


Constraints:

1 <= a.length, b.length <= 10^4
a and b consist only of '0' or '1' characters.
Each string does not contain leading zeros except for the zero itself.

'''

class Solution(object):
    def addBinary(self, a, b):
        """
        :type a: str
        :type b: str
        :rtype: str
        """
        ans = format(int(a, 2)+int(b,2), 'b')
        print(ans)
        return ans


a = "11"
b = "1"
assert "100" == Solution().addBinary(a, b)