using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ConsoleApp1

{

    class Program

    {

        static void Main(string[] args)

        {

            Console.WriteLine("请输入字符串");

            string s1 = Console.ReadLine();

            string s2 = string.Empty;

            int index = s1.LastIndexOf(" ");

            s2 = s1.Substring(index + );

            int n = s2.Length;

            Console.WriteLine("最后一个字符串的长度为{0}", n);

            Console.ReadLine();

        }

    }

}