A non-empty string is called palindrome, if it reads the same from the left to the right and from the right to the left. For example, "abcba", "a", and "abba" are palindromes, while "abab" and "xy" are not.

A string is called a substring of another string, if it can be obtained from that string by dropping some (possibly zero) number of characters from the beginning and from the end of it. For example, "abc", "ab", and "c" are substrings of the string "abc", while "ac" and "d" are not.

Let's define a palindromic count of the string as the number of its substrings that are palindromes. For example, the palindromic count of the string "aaa" is 6 because all its substrings are palindromes, and the palindromic count of the string "abc" is 3 because only its substrings of length 1 are palindromes.

You are given a string s. You can arbitrarily rearrange its characters. You goal is to obtain a string with the maximum possible value of palindromic count.

Input

The first line contains an integer n (1 ≤ n ≤ 100 000) — the length of string s.

The second line contains string s that consists of exactly n lowercase characters of Latin alphabet.

Output

Print string t, which consists of the same set of characters (and each characters appears exactly the same number of times) as string s. Moreover, t should have the maximum possible value of palindromic count among all such strings strings.

If there are multiple such strings, print any of them.

Examples

Input

5
oolol


Output

ololo


Input

16
gagadbcgghhchbdf


Output

abccbaghghghgdfd

Note

In the first example, string "ololo" has 9 palindromic substrings: "o", "l", "o", "l", "o", "olo", "lol", "olo", "ololo". Note, that even though some substrings coincide, they are counted as many times as they appear in the resulting string.

In the second example, the palindromic count of string "abccbaghghghgdfd" is 29.
import java.util.*;
import java.io.*;
import java.math.BigInteger;

public class _practise {
	
	static class FastReader
	{ 
		
		BufferedReader br; 
		StringTokenizer st; 

		public FastReader() 
		{ 
			br = new BufferedReader(new InputStreamReader(System.in)); 
		} 

		String next() 
		{ 
			while (st == null || !st.hasMoreElements()) 
			{ 
				try
				{ 
					st = new StringTokenizer(br.readLine()); 
				} 
				catch (IOException  e) 
				{ 
					e.printStackTrace(); 
				} 
			} 
			return st.nextToken(); 
		} 

		int nextInt() 
		{ 
			return Integer.parseInt(next()); 
		} 

		long nextLong() 
		{ 
			return Long.parseLong(next()); 
		} 

		double nextDouble() 
		{ 
			return Double.parseDouble(next()); 
		} 

		 int[] ia(int n)
		{
			int a[]=new int[n];
			for(int i=0;i<n;i++)a[i]=nextInt();
			return a;
		}
		 int[][] ia(int n , int m)
			{
				int a[][]=new int[n][m];
				for(int i=0;i<n;i++) for(int j=0;j<n ;j++) a[i][j]=nextInt();
				return a;
			}
		 char[][] ca(int n , int m)
			{
				char a[][]=new char[n][m];
				for(int i=0;i<n;i++)
					{
					String x =next();
					for(int j=0;j<n ;j++) a[i][j]=x.charAt(j);
					}
				return a;
			}

		long[] la(int n)
		{
			long a[]=new long[n];
			for(int i=0;i<n;i++)a[i]=nextLong();
			return a;
		}

		String nextLine() 
		{ 
			String str = ""; 
			try
			{ 
				str = br.readLine(); 
			} 
			catch (IOException e) 
			{ 
				e.printStackTrace(); 
			} 
			return str; 
		} 
	}
	static void sort(long[] a) 
	{int n=a.length;Random r=new Random();for (int i=0; i<a.length; i++) {long oi=r.nextInt(n), temp=a[i];a[i]=a[(int)oi];a[(int)oi]=temp;}Arrays.sort(a);}
    static void sort(int[] a) 
    {int n=a.length;Random r=new Random();for (int i=0; i<a.length; i++) {int oi=r.nextInt(n), temp=a[i];a[i]=a[oi];a[oi]=temp;}Arrays.sort(a);}
	public static long sum(long a[])
	{long sum=0; for(long i : a) sum+=i; return(sum);}
	public static long count(long a[] , long x)
	{long c=0; for(long i : a) if(i==x) c++; return(c);}
	public static int sum(int a[])
	{ int sum=0; for(int i : a) sum+=i; return(sum);}
	public static int count(int a[] ,int x)
	{int c=0; for(int i : a) if(i==x) c++; return(c);}
	public static int count(String s ,char ch)
	{int c=0; char x[] = s.toCharArray(); for(char i : x) if(ch==i) c++; return(c);}
	public static boolean prime(int n)
	{for(int i=2 ; i<=Math.sqrt(n) ; i++) if(n%i==0) return false; return true;}
	public static boolean prime(long n)
	{for(long i=2 ; i<=Math.sqrt(n) ; i++) if(n%i==0) return false; return true;}
	 public static int gcd(int n1, int n2)
	  { if (n2 != 0)return gcd(n2, n1 % n2); else return n1;}
	 public static long gcd(long n1, long n2)
	  { if (n2 != 0)return gcd(n2, n1 % n2); else return n1;}
	 public static int[] freq(int a[], int n)
	  { int f[]=new int[n+1]; for(int i:a) f[i]++; return f;}
	 public static int[] pos(int a[], int n)
	  { int f[]=new int[n+1]; for(int i=0; i<n ;i++) f[a[i]]=i; return f;}
	 
	
	 public static long mindig(long n)
	 {
		 long ans=9; while(n>0) { if(n%10<ans) ans=n%10; n/=10; }
		 return ans;
	 }
	 public static long maxdig(long n)
	 {
		 long ans=0; while(n>0) { if(n%10>ans) ans=n%10; n/=10; }
		 return ans;
	 }
	  
	public static boolean palin(String s)
	{
		StringBuilder sb = new StringBuilder();
		sb.append(s);
		String str=String.valueOf(sb.reverse());
		if(s.equals(str))
			return true;
		else return false;
	}
	
	 
	public static void main(String args[])
	{

		FastReader in=new FastReader();
		PrintWriter so = new PrintWriter(new BufferedWriter(new  OutputStreamWriter(System.out)));
		_practise ob = new _practise();
		
		//int t = in.nextInt();
		int t = 1;
		
		
		 while(t-->0)
		 {
			
			 int n = in.nextInt();
				String s = in.next();
			char ch[] = s.toCharArray();
			Arrays.sort(ch);
				  so.println(String.valueOf(ch));
			
		 }
		
		
		
		
		so.flush();

		/*String s = in.next();
		 * Arrays.stream(f).min().getAsInt()
		 * BigInteger f = new BigInteger("1"); 1 ke jagah koi bhi value ho skta jo aap 
		 *                                       initial value banan chahte
			int a[] = new int[n];
			 Stack<Integer> stack = new Stack<Integer>();
			 	Deque<Integer> q = new LinkedList<>(); or Deque<Integer> q = new ArrayDeque<Integer>();
			PriorityQueue<Long> pq = new PriorityQueue<Long>();
			ArrayList<Integer> al = new ArrayList<Integer>(); 
			StringBuilder sb = new StringBuilder();
			HashSet<Integer> st = new LinkedHashSet<Integer>();
			Set<Integer> s = new HashSet<Integer>();
			Map<Long,Integer> hm = new HashMap<Long, Integer>(); //<key,value>
			 for(Map.Entry<Integer, Integer> i :hm.entrySet())
			HashMap<Integer, Integer> hmap = new HashMap<Integer, Integer>();
			so.println("HELLO");
			Arrays.sort(a,Comparator.comparingDouble(o->o[0]))
			 Arrays.sort(a, (aa, bb) -> Integer.compare(aa[1], bb[1]));*/
	}
}