using System;

public class Program

{

    static double Raz_2(double a, double b,double c)

    {

        double result = a*a-b*b=(a-b)*(a+b);

        return result;

    }

    public static void Main()

    {

        double a,b,c;

        double Raz_2(2,4);

​

        Console.WriteLine(result);

    }

}