using System;
using System.Numerics;
using System.Linq;

namespace Hamming {

    class MainClass {

        public static BigInteger Hamming(int n) {
            BigInteger two = 2, three = 3, five = 5;
            var h = new BigInteger[n];
            h[0] = 1;
            BigInteger x2 = 2, x3 = 3, x5 = 5;
            int i = 0, j = 0, k = 0;

            for (int index = 1; index < n; index++) {
                h[index] = BigInteger.Min(x2, BigInteger.Min(x3, x5));
                if (h[index] == x2) x2 = two * h[++i];
                if (h[index] == x3) x3 = three * h[++j];
                if (h[index] == x5) x5 = five * h[++k];
            }
            return h[n - 1];
        }

        public static void Main(string[] args) {
            Console.WriteLine(string.Join(" ", Enumerable.Range(1, 20).ToList().Select(x => Hamming(x))));
            Console.WriteLine(Hamming(1691));
            Console.WriteLine(Hamming(1000000));
        }
    }
}