using System;

using System.Threading;

​

namespace Program

{

    public class Program

    {

        public static void Main(string[] args)

        {

            int i = 5;

            object reference = i;

            bool wasTaken = false;

            try

            {

                Monitor.Enter(reference, ref wasTaken);

            }

            finally

            {

                if (wasTaken)

                {

                    Monitor.Exit(reference);

                }

            }

        }

    }

}