using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    private static bool IsPrimeNumber1(int number)

    {

        if (number == 1)

        {

            return false;

        }

        else if (number == 2 || number == 3)

        {

            return true;

        }

        var i = 2;

        var squared = Math.Sqrt(number);

        while (i <= squared)

        {

            if (number % i == 0)

            {

                return false;

            }

            i++;

        }

        return true;

    }

    private static bool IsPrimeNumber2(int number)

    {

        if (number == 1)

        {

            return false;

        }

        else if (number == 2 || number == 3)

        {

            return true;

        }

        else if (number % 6 == 1 || number % 6 == 5)

        {

            var maxInt = (int)Math.Sqrt(number);

            if (number % maxInt == 0)

            {

                return false;

            }

            return true;

        }

        return false;

    }

    public static void Main()

    {

        var max = 1000000;

​

​

        var ranges = Enumerable.Range(2, max-1).Where(p => Enumerable.Range(2, (int)Math.Sqrt(p) - 1).All(q => p % q > 0));

        foreach(var range in ranges)

        {

            Console.WriteLine(range);

        }

​

        /*

        var values = new List<bool>(new bool[max]);

        for(var n = 1; n <= max; n++)

        {

            values[n-1] = IsPrimeNumber1(n);

        }

        for(var i = 0; i < values.Count(); i++)

        {

            if (values[i])

            {

                Console.WriteLine(i + 1);

            }

        }

    */

    }

}