using System; 

 public class GFG  

{ 

  static void descOrder(char[] s)  

    { 

        Array.Sort(s); 

        reverse(s); 

    } 

   static void reverse(char[] a)  

    { 

        int i, n = a.Length; 

        char t; 

        for (i = 0; i < n / 2; i++)  

        { 

            t = a[i]; 

            a[i] = a[n - i - 1]; 

            a[n - i - 1] = t; 

        } 

    }

    public static void Main(String[] args) 

    { 

        char[] s = "geeksforgeeks".ToCharArray(); 

        descOrder(s); // function call 

        Console.WriteLine(String.Join("",s)); 

    } 

}