Prak3 II (4)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Prak3_II__4_
{
    class Program
    {
        static void Main(string[] args)
        {
            double x, y, x2, y2;
            Console.Write("Введите x: ");
            x = double.Parse(Console.ReadLine());
            Console.Write("Введите y: ");
            y = double.Parse(Console.ReadLine());
            x2 = x * x;
            y2 = y * y;
            if (x2 + y2 < 64 && x2 + y2 > 9 && x < 0)
                Console.WriteLine("Да");
            else if (x2 + y2 > 64 || x2 + y2 < 9 || x > 0)
                Console.WriteLine("Нет");
            else
                Console.WriteLine("На границе");
            Console.ReadKey();


        }
    }
}