using System;

public class Program

{

    public static void Main()

    {

        string str;

  char[] arr1;

  int pos, l, ln, c = 0;

               Console.Write("\n\nExtract a substring from a given string:\n");

               Console.Write("--------------------------------------------\n");  

               Console.Write("Input the string : ");

               str = Console.ReadLine();    

               ln=str.Length;

               arr1 = str.ToCharArray(0, ln);

​

               Console.Write("Input the position to start extraction :");

               pos= Convert.ToInt32(Console.ReadLine()); 

               Console.Write("Input the length of substring :");

               l= Convert.ToInt32(Console.ReadLine()); 

 Console.Write("The substring retrieve from the string is : ");

   while (c < l) 

   {

   Console.Write(arr1[pos+c-1]);

      c++;

   }

   Console.Write("\n\n");

    }

}