[CodeKata] -11

def complex_number_multiply(a, b):
    a, b = a.replace('i', ''), b.replace('i', '')
    a, b = a.split('+'), b.split('+')
    
    return f"{int(a[0])*int(b[0])-(int(a[1])*int(b[1]))}+{int(a[0])*int(b[1])+int(a[1])*int(b[0])}i"

def complex_number_multiply(a, b):
  a1, a2 = map(int, a[:-1].split('+'))
  b1, b2 = map(int, b[:-1].split('+'))
  
  return '%d+%di' % (a1 * b1 - a2 * b2, a1 * b2 + a2 * b1)