JAVA Help

import java.util.*;
class word_sort
{
    public static void main()
    {
        Scanner s=new Scanner(System.in);
        System.out.println("Enter the word");
        String st=s.next();
        st=st.toUpperCase();
        char ch;
        String aw="",dw="";
        for(int i=65;i<=90;i++)
        {
            for(int j=0;j< st.length();j++)
            {
                ch=st.charAt(j);
                if (ch==i)
                {
                    aw=aw+ch;
                    dw=ch+dw;
                }
            }
        }
        System.out.println("ORIGINAL:"+st);
        System.out.println("ASCENDING:"+aw);
        System.out.println("DESCENDING:"+dw);
    }
}