human
Solve in Python:
Given two strings representing two complex numbers.

You need to return a string representing their multiplication. Note i2 = -1 according to the definition.

Example 1:

Input: "1+1i", "1+1i"
Output: "0+2i"
Explanation: (1 + i) * (1 + i) = 1 + i2 + 2 * i = 2i, and you need convert it to the form of 0+2i.


Example 2:

Input: "1+-1i", "1+-1i"
Output: "0+-2i"
Explanation: (1 - i) * (1 - i) = 1 + i2 - 2 * i = -2i, and you need convert it to the form of 0+-2i.


Note:

The input strings will not have extra blank.
The input strings will be given in the form of a+bi, where the integer a and b will both belong to the range of [-100, 100]. And the output should be also in this form.
 What is a the Python program you requested?
assistant
#Here is the Python program you requested.

class Solution:
     def complexNumberMultiply(self, a, b):
         """
         :type a: str
         :type b: str
         :rtype: str
         """
         
         a1 = int(a.split('+')[0])
         a2 = int(a.split('+')[1].replace('i',''))
         b1 = int(b.split('+')[0])
         b2 = int(b.split('+')[1].replace('i',''))
         
         m1 = a1 * b1 - a2 * b2
         m2 = a1 * b2 + a2 * b1
         
         return str(m1) + '+' + str(m2) + 'i'