using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public class Stock

    {

        public int SwatchID {get;set;}  

    }

    public static void Main()

    {

        var stocks = new List<Stock>

        {

            new Stock{SwatchID = 1} 

        };

        int? swatchID = stocks.FirstOrDefault(p=> p.SwatchID != 0).SwatchID;

        Console.WriteLine(swatchID);

    }

}