using System;
using System.Collections.Generic;

namespace ConsoleApplication1
{
    public class Program
    {
        public static void Main()
        {
            Outer.Nested.CreateInstance(34);
            Outer.Nested.CreateInstance(5);
            Outer.Nested.CreateInstance(21);
            Console.WriteLine(Outer.Nested.CompareRecord(0, 34));
        }
    }

    public class Outer
    {
        private readonly int _field;

        public Outer(int field)
        {
            _field = field;
        }

        public static class Nested
        {
            private static readonly List<Outer> ListOfNested = new List<Outer>();

            public static void CreateInstance(int input)
            {
                Outer record = new Outer(input);
                ListOfNested.Add(record);
            }

            public static bool CompareRecord(int location, int num)
                => ListOfNested[location]._field == num;
        }
    }
}