using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Równanie kwadratowe Ax^2+Bx+C=0");

        Console.WriteLine("Wprowadź A");

        string a = Console.ReadLine();

        double A = Double.Parse(a.Replace(',', '.'), NumberStyles.Number, CultureInfo.InvariantCulture);

        Console.WriteLine("Wprowadź B");

        string b = Console.ReadLine();

        double B = Double.Parse(b.Replace(',', '.'), NumberStyles.Number, CultureInfo.InvariantCulture);

        Console.WriteLine("Wprowadź C");

        string c = Console.ReadLine();

        double C = Double.Parse(c.Replace(',', '.'), NumberStyles.Number, CultureInfo.InvariantCulture);

        double D = Math.Pow(B, 2) - 4 * A * C;

           if (D > 0 || D == 0)

            {

             double  x1 = (-B + Math.Sqrt(D)) / (2 * A);

             double  x2 = (-B - Math.Sqrt(D)) / (2 * A);

               Console.WriteLine("x1= {0}\n x2= {1}", x1, x2);

               Console.ReadLine();

            }

           else

           {

               Console.WriteLine("Równanie nie ma rozwiązań");

               Console.ReadLine();

           }

        bool T= D>=0;

        switch (T)

        {

                case true:

               double  x1 = (-B + Math.Sqrt(D)) / (2 * A);

               double  x2 = (-B - Math.Sqrt(D)) / (2 * A);

               Console.WriteLine("x1= {0}\n x2= {1}", x1, x2);

               Console.ReadLine();

                break;

            default:

               Console.WriteLine("Równanie nie ma rozwiązań");

               Console.ReadLine();

                break;

        }

    }

}