Challenge Primes without numbers

Question

Don't get confused by the title :P
The challenge is to check if a user input is a prime or even print a list of primes without using any numbers in your code.
(for example int a = 0 is forbidden, however a = Console.ReadLine() isn't as you are not using a number directly)

I don't think this challenge is too hard but I still would like to see some unique ways to work around the problem :D

Happy coding ^^

Answer 1

one(with requires Two) liner in ruby

https://code.sololearn.com/cwhg6I6J0n77/#rb

Answer 2

ok

https://code.sololearn.com/cEQEPihWHmnB/?ref=app

Answer 3

c# pretty straight forward code, but at least it has no bugs (I think)
https://code.sololearn.com/cOlXJY7243WU/#cs