04. Sieve of Eratosthenes

using System;

namespace _04._Sieve_of_Eratosthenes_Veronika
{
    class Program
    {
        static void Main(string[] args)
        {
            int input = int.Parse(Console.ReadLine());
            bool[] primer = new bool[input + 1];

            for (int i = 0; i < primer.Length; i++)
            {
                primer[i] = true;
            }
            if (primer.Length == 1)
            {
                primer[0] = false;
            }
            else
            {
            primer[0] = false;
            primer[1] = false;
            }

            for (int i = 2; i < primer.Length; i++)
            {
                if (primer[i])
                {
                    Console.Write($"{i} ");

                    for (int j = 2 * i; j < primer.Length; j+=i)
                    {
                        primer[j] = false;
                    }
                }
            }
        }
    }
}