Do you know the book Murderous Maths, in the Horrible Science series? In the book, the Laplace Princess' "ridiculous" cipher might be interesting enough and simple enough to be a code-golf challenge.
The original cipher looks like this:
Please read primes elephant help you me like cold
The nth word is only meaningful if it is a prime. So, the cipher becomes:
read primes help me
Your task is to write a program that inputs the cipher and outputs the plaintext.
You can take the input in any acceptable forms, e. g. an list of words.
The input will only consist of printable-ASCII characters.
You can use 0-based index or 1-based index.
A "Word" includes any punctuation. For example:
This is, "a" great test! I think.
is, "a" test! think.