Не работает код сортировки и отбора уникальных значений - C#

using System;
using System.Collections.Generic;
using System.IO;
 
namespace WindowsFormsApplication1
{
    public partial class Form1
    {
        static void Main()
        {
            List<double> resList = new List<double>();
            using (StreamReader sr1 = new StreamReader("1.txt"))
            {
                while (sr1.EndOfStream)
                    resList.Add(double.Parse(sr1.ReadLine()));
            }
            using (StreamReader sr2 = new StreamReader("2.txt"))
            {
                while (sr2.EndOfStream)
                    resList.Add(double.Parse(sr2.ReadLine()));
            }
            resList.Sort();
            using (StreamWriter wr = new StreamWriter("3.txt"))
            {
                foreach (double s in resList)
                    wr.WriteLine(s);
            }
            Console.ReadLine();
        }
    }
}