static void Main(string[] args)
        {
            double shifa, shuilv, yingfa, sukou, koushui, a;
            double qizheng = 3500;
            Console.WriteLine("请输入你的发应工资");
            yingfa = Convert.ToDouble(Console.ReadLine());
            a = yingfa - qizheng;//*****差值*****
//分两个阶段高于3500和低于3500
            if (a <= 0 && a > -1500)
            {
                Console.WriteLine("buyong");
            }
            else if (a > 0 && a <= 1500)        //     <=1500        3%    0       
            {
                sukou = 0; shuilv = 0.03;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的应发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else if (a > 1500 && a <= 4500)   //1500<a<=4500    10%    105
            {
                sukou = 105; shuilv = 0.1;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else if (a > 4500 && a <= 9000)//4500<a<=9000    20%    555
            {
                sukou = 555; shuilv = 0.2;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的应发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else if (a > 9000 && a <= 35000)  //9000<a<=35000    25%    1005
            {
                sukou = 1005; shuilv = 0.25;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的应发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else if (a > 35000 && a <= 55000)//35000<a<=55000    30%    2755
            {
                sukou = 2755; shuilv = 0.3;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的应发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else if (a > 55000 && a <= 80000)//55000<a<=80000    35%    5505
            {
                sukou = 5505; shuilv = 0.35;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的应发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else if (a > 80000)//80000<a        45%    13505
            {
                sukou = 13505; shuilv = 0.45;
                koushui = a * shuilv - sukou;
                shifa = yingfa + koushui;
                Console.WriteLine("你的应发工资和扣税是:{0},{1}", shifa, koushui);
            }
            else
            {
                Console.WriteLine("输入有误");
            }
        }