using System;

​

public class Program

{

    public static void Main()

    {

        int i,j,m,n;

        string s,c,d;

        char[] a;

        char ch;

        Console.Write("enter a string");

        s=Console.ReadLine();

        a=s.ToCharArray();

        Console.WriteLine("enter the starting index");

        c=Console.ReadLine();

         n = Convert.ToInt32(c);

         Console.WriteLine("Your input: {0}",n);

        Console.WriteLine("enter the last index");

        d = Console.ReadLine();

         m = Convert.ToInt32(d);

        Console.WriteLine("Your input: {0}",m);

            for (i = n; i <=m; i++) 

            {

            for (j = i + 1; j <= m; j++)

            {

                if (a[i] < a[j])

                { 

                    ch = a[i]; 

                    a[i] = a[j]; 

                    a[j] = ch; 

                }

            }

            }

        for(i=0;i<a.Length;i++)

        {

            Console.Write(a[i]);

        }

        }

}

​