using System;

namespace LowestNatural

{

    public class Program

    {

        public static void Main(string[] args)

        {

            var sequence1 = new[] { 3, 4, -1, 1};

            var sequence2 = new[] { 1, 2, 0};

            var sequence3 = new[] { 5, 8, 3, 1, 4, 6};

            var sequence4 = new[] { 7, 8, 9, 13, 5, 21, 3};

            var sequence5 = new[] { -5, -2, 0, 2, -4};

            var sequence6 = new[] { -5, -2, 2, 1, -4};

            var lowestNatural1 = LowestNatural(sequence1);

            var lowestNatural2 = LowestNatural(sequence2);

            var lowestNatural3 = LowestNatural(sequence3);

            var lowestNatural4 = LowestNatural(sequence4);

            var lowestNatural5 = LowestNatural(sequence5);

            var lowestNatural6 = LowestNatural(sequence6);

            if (lowestNatural1 != 2) throw new System.Exception("Error");

            if (lowestNatural2 != 3) throw new System.Exception("Error");

            if (lowestNatural3 != 2) throw new System.Exception("Error");

            if (lowestNatural4 != 1) throw new System.Exception("Error");

            if (lowestNatural5 != 1) throw new System.Exception("Error");

            if (lowestNatural6 != 3) throw new System.Exception("Error");

            if (LowestNatural(new int[]{}) != 1) throw new System.Exception("Error");

            if (LowestNatural(null) != 1) throw new System.Exception("Error");

            Console.WriteLine("All good");

        }

        private static int LowestNatural(int[] sequence)

        {

            return 0;

        }

    }

}