using System;

class test3{
    static void Main(){
        Console.Write("请输入任意一个三位数:");
        string s=Console.ReadLine();
        int x=Convert.ToInt32(s);
        
        Console.WriteLine("逆序后为：{0}{1}{2}",(x%100)%10,(x-(x/100)*100)/10,x/100);
        Console.ReadKey();
    }
}

Console.WriteLine("请输入：");
            int a;
            string s = Console.ReadLine();
            a = Convert.ToInt32(s);
            int b = 0;
            while (a > 0)
            {
                b = b * 10 + a % 10;
                a = a / 10;
               
            }
            Console.WriteLine("倒序输出后的数：{0}", b);