using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication14
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("求其中的後幾位？");
int i = Convert.ToInt32( Console.ReadLine());
string str = "12345678901234567890";
string substr;
substr = str.Substring(str.Length - i, i);
Console.WriteLine(substr);
Console.ReadLine();
}
}
}
}