A complex number is a number of the form \(a + bi\), whereby \(a\) and \(b\) are constants, and \(i\) is a special value that is defined as the square root of -1. Of course, you never try to actually calculate what the square root of -1 is, as that gives a runtime error; in complex numbers, you always let the \(i\) remain. For instance, the complex number \(3 + 2i\) cannot be simplified any further.

Multiplication of two complex numbers \(a + bi\) and \(c + di\) is defined as

\[(a\times c - b\times d) + (a\times d + b\times c)i\]

Assignment

We represent a complex number as a tuple of two numeric values. Write a function product that calculates the multiplication of two complex numbers.

Example

>>> product((3, 4), (7, 2))
(13, 34)