Hello everyone. I started to read "The Book" to learn rust here a problem I've encounter. I'm no programmer and try many thing in the code to fix it myself but to no avail. If someone had the kindness to explain me what is my mistake I would kindly appreciate thank you.
Here is a picture of what the problem seems to be.
Here is rustc version:
rustc 1.49.0 (e1884a8e3 2020-12-29)