using System;
using System.Collections.Generic;
using System.Linq;
using System.Collections;

namespace ConsoleApp2
{
    class Progam
    {
        public static void Main()
        {
            var result = FindNumbers();
            Console.WriteLine(result[0]);
            Console.WriteLine(result[1]);
            Console.WriteLine(result[2]);
            Console.WriteLine(result[3]);
            Console.ReadKey();
        }
        private static int[] FindNumbers()
        {
            var result = new int[5];
            for (var i = 100000; i < 150000; i++)
            {
                if (Check(i, i + 1, i + 2, i + 3).Length == 4)
                    result = Check(i, i + 1, i + 2, i + 3);
            }
            return result;
        }
        private static int[] Check(int first, int second, int third, int forth)
        {
            var primeList = CreatePrimeList(100000);
            var firstPrimes = FindPrimes(primeList, first);
            var secondPrimes = FindPrimes(primeList, second);
            var thirdPrimes = FindPrimes(primeList, third);
            var forthPrimes = FindPrimes(primeList, forth);
            var AllPrimes = forthPrimes.Concat(thirdPrimes.Concat(firstPrimes.Concat(secondPrimes))).ToArray();
            if (AllPrimes.Length == 16)
                return new int[4] { first, second, third, forth };
            else return new int[1] { 0 };
        }
        private static int[] FindPrimes(int[] primes, int number)
        {
            var result = new List<int>();
            while (number > 1)
            {
                for (var i = 0; i < primes.Length; i++)
                {
                    if (result.Count > 3)
                        break;
                    if (number % primes[i] == 0)
                        result.Add(primes[i]);
                    while (number % primes[i] == 0)
                        number /= primes[i];
                }
                break;
            }
            return result.ToArray();
        }
        private static int[] CreatePrimeList(int upperLimit)
        {

            int sieveBound = (int)(upperLimit - 1) / 2;
            int upperSqrt = ((int)Math.Sqrt(upperLimit) - 1) / 2;

            BitArray PrimeBits = new BitArray(sieveBound + 1, true);

            for (int i = 1; i <= upperSqrt; i++)
            {
                if (PrimeBits.Get(i))
                {
                    for (int j = i * 2 * (i + 1); j <= sieveBound; j += 2 * i + 1)
                    {
                        PrimeBits.Set(j, false);
                    }
                }
            }

            List<int> numbers = new List<int>((int)(upperLimit / (Math.Log(upperLimit) - 1.08366)));
            numbers.Add(2);
            for (int i = 1; i <= sieveBound; i++)
            {
                if (PrimeBits.Get(i))
                {
                    numbers.Add(2 * i + 1);
                }
            }

            return numbers.ToArray();
        }
    }
}