# Ryan Thompson

## Week 162 Solutions

### Task 1 › ISBN-13

 * [Perl](perl/ch-1.pl)

### Task 2 › Wheatstone–Playfair Cipher

 * [Perl](perl/ch-2.pl)

## Blogs

 * [ISBN-13](https://ry.ca/2022/04/isbn-13)
 * [Wheatstone–Playfair Cipher](https://ry.ca/2022/04/playfair-cipher)