using System;

public class Program

{

    public static void Main()

    {

        int a,b,c,d;

        double x, x1, x2;

        Console.WriteLine("Nhap a:");

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

        Console.WriteLine("Nhap b:");

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

        Console.WriteLine("Nhap c:");

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

        float d = b*d-4*a*c;

        if(d == 0)

        {

            x=-b/(2.0*a);

            Console.WriteLine("phuong trinh co mot nghiem",x);

        }

        else if (d>0)

        {

            Console.WriteLine("phuong trinh co 2 nghiem");

        x1 = (-b + Math.Sqrt(d)) / (2 * a);

        x2 = (-b - Math.Sqrt(d)) / (2 * a);

        Console.Write("Nghiem thu nhat: x1 = {0}\n", x1);

        Console.Write("Nghiem thu nhat: x2 = {0}\n", x2);

        }

        else

        Console.WriteLine("phuong trinh vo nghiem");

        }

    }

}