leetcode: 67. Add Binary

# Given two binary strings, return their sum (also a binary string).
#
# For example,
# a = "11"
# b = "1"
# Return "100".

class Solution():
    def addBinary(self, a, b):
        num = int(a, 2) + int(b, 2)
        return bin(num)[2:]


if __name__ == '__main__':
    assert Solution().addBinary('11', '1') == '100'