C# 计算球体积：多组数据输入

using System;

class Program
{
    static void Main(string[] args)
    {
        const double PI = 3.1415927;

        double radius = 0;
        while (true)
        {
            radius = double.Parse(Console.ReadLine());

            if (radius == -1)
            {
                break;
            }

            double volume = 4.0 / 3.0 * PI * Math.Pow(radius, 3);
            Console.WriteLine(volume.ToString('F3'));
        }
    }
}