':type a: str
:type b: str
:rtype: str'

def complexNumberMultiply(self, a, b):

    (ra, ia) = map(int, a[:(-1)].split('+'))
    (rb, ib) = map(int, b[:(-1)].split('+'))
    return ('%d+%di' % (((ra * rb) - (ia * ib)), ((ra * ib) + (ia * rb))))
