Alright, I'll be giving away this $10,000 Gucci XBox to a follower who retweets this in the next 24 hours. I'll ship it anywhere on earth. Good luck.
Here's what's inside: https://t.co/Mung64czZs
Sieve of Eratosthenes: an ancient algorithm for finding all prime numbers up to any given limit.
Make a list of all the integers ≤ n. Strike out the multiples of all primes ≤ √n, then the numbers that are left are the primes.