human
Write me a Python code to print string t, which consists of the same set of characters (and each characters appears exactly the same number of times) as string s given the following:
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.
Using python can you solve the prior task?
assistant
#Here is Python code to print string t, which consists of the same set of characters (and each characters appears exactly the same number of times) as string s.

"""
What I cannot create, I do not understand.

https://github.com/Cheran-Senthil/PyRival
Copyright (c) 2018 Cheran Senthilkumar
"""
# IMPORTS---------------------------------------------------------------------#
from __future__ import division, print_function

import itertools
import sys
from atexit import register
from io import BytesIO

# import cmath
# import math
# import operator as op
# import random
# from bisect import bisect, bisect_left
from collections import Counter, defaultdict, deque
# from copy import deepcopy
# from cPickle import dumps
# from decimal import Decimal, getcontext
# from difflib import SequenceMatcher
# from fractions import Fraction, gcd
# from heapq import heappop, heappush
# from Queue import PriorityQueue, Queue

# PYTHON3---------------------------------------------------------------------#
class dict(dict):
    def items(self):
        return dict.iteritems(self)

    def keys(self):
        return dict.iterkeys(self)

    def values(self):
        return dict.itervalues(self)

filter = itertools.ifilter
map = itertools.imap
zip = itertools.izip

input = raw_input
range = xrange

# FASTIO----------------------------------------------------------------------#
# sys.stdout = BytesIO()
# register(lambda: sys.__stdout__.write(sys.stdout.getvalue()))
# sys.stdin = BytesIO(sys.stdin.read())

# input = lambda: sys.stdin.readline().rstrip()
# print = lambda *args: sys.stdout.write(' '.join(str(x) for x in args) + '\n')
# flush = sys.stdout.flush

# SETTINGS--------------------------------------------------------------------#
# getcontext().prec = 100
# sys.setrecursionlimit(100000)

# CONSTANTS-------------------------------------------------------------------#
MOD = 1000000007
INF = float('+inf')

ASCII_LOWERCASE = 'abcdefghijklmnopqrstuvwxyz'
ASCII_UPPERCASE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

# MAIN------------------------------------------------------------------------#
def main():
    n = int(input())
    print(''.join(sorted(input())))

if __name__ == '__main__':
    main()