Good morning! Here's your coding interview problem for today.

This problem was asked by Nest.

Create a basic sentence checker that takes in a stream of characters and determines whether they form valid sentences. If a sentence is valid, the program should print it out.

We can consider a sentence valid if it conforms to the following rules:

The sentence must start with a capital letter, followed by a lowercase letter or a space.
All other characters must be lowercase letters, separators (,,;,:) or terminal marks (.,?,!,‽).
There must be a single space between each word.
The sentence must end with a terminal mark immediately following a word.