//package com.company.Algorithm.DP;
import java.io.*;
import java.util.*;
public class temp {
    public static void main(String[]args)throws IOException
    {
        BufferedReader buf =new BufferedReader(new InputStreamReader(System.in));
        int n=Integer.parseInt(buf.readLine());
        String p=buf.readLine();
        StringBuilder ams=new StringBuilder("");
        char[]est=p.toCharArray();
        Arrays.sort(est);
        for(char ch:est)
        {
            ams.append((char)('z'-ch-'a'));
        }
        System.out.println(ams);
    }
}