Exercise

# Coprime number sequence

Two numbers \(a\) and \(b\) are coprime if their Greatest Common Divisor (GCD) is 1. GCD is the largest positive number that divides two given numbers \(a\) and \(b\). For example, the numbers 7 and 9 are coprime because their GCD is 1.

Given two lists `list1`

and `list2`

, your task is to create a new list `coprimes`

that contains all the coprime pairs from `list1`

and `list2`

.

But first, you need to write a function for the GCD using the following algorithm:

- check if \(b = 0\)
- if true, return \(a\) as the GCD between \(a\) and \(b\)
- if false, go to step 2

- make a substitution \(a \leftarrow b\) and \(b \leftarrow a \% b\)
- go back to step 1

Instructions 1/2

**undefined XP**

- Define the while loop as described in the context.
- Complete the return statement.