using System;

​

public class NormalRandom : Random

    {

        public double NextDouble(double mean, double variance)

        {

            double z = Math.Sqrt(-2 * Math.Log(base.NextDouble())) * Math.Cos(2 * Math.PI * base.NextDouble());

            return Math.Sqrt(variance) * z + mean;

        }

    }

​

public class Program

{

    public static void Main()

    {

        NormalRandom rand = new NormalRandom();

        Console.WriteLine(rand.NextDouble(3d, 2d));

    }

}