using System;

public class Program

{

    public static void Main()

    {

        int a,b,c;

        Console.WriteLine("Nhap va a:");

        a = int.Parse(Console.ReadLine());

        Console.WriteLine("Nhap va b:");

        b = int.Parse(Console.ReadLine());

        Console.WriteLine("Nhap va c:");

        c = int.Parse(Console.ReadLine());

        double delta = b*b-4*a*c;

        double d = Math.Sqrt(delta);

        if (delta < 0)

            {

            Console.Write("Phuong trinh vo nghiem");

            }

        if (delta == 0)

            {

                Console.Write("Phuong trinh co nghiem la {0}",-1.0*b/(2*a));

            }

        if (delta > 0)

            {

            Console.Write("Phuong trinh co nghiem la {0}\n",(-1.0*b+d)/(2*a));

            Console.Write("Phuong trinh co nghiem la {0}",(-1.0*b-d)/(2*a));              

            }

        /*

        double So_nam, So_tien_gui, Tien;

        Console.Write("So tien gui la: ");

        So_tien_gui = double.Parse(Console.ReadLine());

        Console.Write("So nam gui la: ");

        So_nam = double.Parse(Console.ReadLine());

        Tien = So_nam*So_tien_gui*1.07;

        Console.WriteLine("So tien nhan duoc sau {0} gui la: {1}",So_nam,Tien);

        Console.ReadLine();

        */

    }

}