Problems when accessing shared data using multithreading programming

Program.cs

namespace manage_multithreading
{
    class Program
    {
        static void Main(string[] args)
        {
            int theAlmightyZero = 0;

            Task newAmazingTask = Task.Run(() =>
            {
                for (int i = 0; i < 1000000; i++)
                    theAlmightyZero++;
            });

            for (int j = 0; j < 1000000; j++)
                theAlmightyZero--;

            newAmazingTask.Wait();

            Console.WriteLine("Here it comes a ZERO value! "+theAlmightyZero);
            Console.ReadLine();
        }
    }
}