Error type help

Exercise : https://www.codecademy.com/courses/learn-c-plus-plus/lessons/cpp-functions/exercises/return-types-cpp-functions

Hello,
See the example with blue ?
Capture
I wanted, for revision, to guess what type of error it was (compile-time error, run-time error…) and I really can’t distinguish them. I could tell you the difference between types if you asked me to but I won’t recognize one if not from the ezample list given. To me they all seem logical ; it could be compile-time because the syntax is incorrect (the return has to be at the end), run-time error (cause you’re asking the computer to do something after the return which is impossible) and a logic error because this function is illogically written.

Thanks.

why would there be an error?
that’s a valid function.