---

using System;

class Program
{
    static void Main()
    {
        Console.Write("a = ");
        double a = double.Parse(Console.ReadLine());
        Console.Write("b = ");
        double b = double.Parse(Console.ReadLine());
        Console.Write("c = ");
        double c = double.Parse(Console.ReadLine());

        double D = b * b - 4 * a * c;
        Console.WriteLine($"D = {D}");

        if (D > 0)
        {
            double x1 = (-b + Math.Sqrt(D)) / (2 * a);
            double x2 = (-b - Math.Sqrt(D)) / (2 * a);
            Console.WriteLine($"x1 = {x1}");
            Console.WriteLine($"x2 = {x2}");
        }
        else if (D == 0)
        {
            double x = -b / (2 * a);
            Console.WriteLine($"x = {x}");
        }
        else
        {
            Console.WriteLine("Нет действительных корней");
        }

        Console.ReadKey();
    }
}