2
aaab
 2
babac
 2
aaaaaabbbb
 1
aabaab
 2
aabbbbccccccdddddddd
 2
abba
 2
aaaazzzz
 250
cececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececece
 3
aaaaaaaaacccdddddd
 2
aabaab
 1
aaaaa
 7
abacaba
 2
aaaabbbb
 5
aaaaa
 1
aaa
 2
aaazz
 3
aabaaaaabb
 2
aaaa
 2
aa
 3
bbbccc
 15
abaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaaabaabbbcababaaa
 1
a
 2
bbaaaa
 2
aaaabb
 2
aabbbb
 2
aaaaaazz
 3
aaaaaaaaacccbbbbbb
 2
bbbbaa
 2
aaaazz
 2
aazzzz
 2
acaccc

-1
 -1
 aaabbaaabb aaaabb
 abbcccddddabbcccdddd abab
 aazzaazz cececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececececece
 aaacddaaacddaaacdd aabaab
 aaaaa
 -1
 aabbaabb
 aaaaa
 aaa
 -1
 -1
 aaaa
 aa
 bcbcbc
 aaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbcaaaaaaaabbbbbbc a
 aabaab
 aabaab
 abbabb
 aaazaaaz aaabbcaaabbcaaabbc
 abbabb
 aazaaz azzazz
 accacc

"""Template for Python Competitive Programmers prepared by Mayank Chaudhary aka chaudhary_19"""

# to use the print and division function of Python3
from __future__ import division, print_function

"""value of mod"""
MOD = 10 ** 9 + 7

"""use resource"""
# import resource
# resource.setrlimit(resource.RLIMIT_STACK, [0x100000000, resource.RLIM_INFINITY])

"""uncomment next 4 lines while doing recursion based question"""
# import threading
# threading.stack_size(2**27)
import sys

# sys.setrecursionlimit(10**6)

"""uncomment next 7 lines while doing nCr question"""
# fact=[1]
# for i in range(1,100001):
#    fact.append((fact[-1]*i)%mod)
# ifact=[0]*100001
# ifact[100000]=pow(fact[100000],mod-2,mod)
# for i in range(100000,0,-1):
#    ifact[i-1]=(i*ifact[i])%mod

"""uncomment modules according to your need"""
from bisect import bisect_left, bisect_right, insort
# import itertools
# import collections
# import math
# import heapq
# from random import randint as rn
# from Queue import Queue as Q

'''
def modinv(n, p):
    return pow(n, p - 2, p)
'''

'''
def ncr(n, r, p):  # for using this uncomment the lines calculating fact and ifact
    t = ((fact[n]) * ((ifact[r] * ifact[n - r]) % p)) % p
    return t
'''


def get_ints(): return map(int, sys.stdin.readline().strip().split())
def get_array(): return list(map(int, sys.stdin.readline().strip().split()))
def input(): return sys.stdin.readline().strip()


'''
def GCD(x, y):
    while (y):
        x, y = y, x % y
    return x
'''

"""*******************************************************"""

def get_xor(n):
    return [n,1,n+1,0][n%4]


def main():

    n = int(input())
    string = input()

    mydict = dict()
    for i in string:
        mydict[i] = mydict.get(i, 0)+1

    flag = 0
    ans = ''
    for i in mydict:
        if mydict[i]%n==0:
            ans += i*(mydict[i]//n)
        else:
            flag = 1
            break

    if flag:
        print(-1)
    else:
        print(ans*n)




""" -------- Python 2 and 3 footer by Pajenegod and c1729 ---------"""

py2 = round(0.5)
if py2:
    from future_builtins import ascii, filter, hex, map, oct, zip

    range = xrange

import os, sys
from io import IOBase, BytesIO

BUFSIZE = 8192


class FastIO(BytesIO):
    newlines = 0

    def __init__(self, file):
        self._file = file
        self._fd = file.fileno()
        self.writable = "x" in file.mode or "w" in file.mode
        self.write = super(FastIO, self).write if self.writable else None

    def _fill(self):
        s = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
        self.seek((self.tell(), self.seek(0, 2), super(FastIO, self).write(s))[0])
        return s

    def read(self):
        while self._fill(): pass
        return super(FastIO, self).read()

    def readline(self):
        while self.newlines == 0:
            s = self._fill();
            self.newlines = s.count(b"\n") + (not s)
        self.newlines -= 1
        return super(FastIO, self).readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.getvalue())
            self.truncate(0), self.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        if py2:
            self.write = self.buffer.write
            self.read = self.buffer.read
            self.readline = self.buffer.readline
        else:
            self.write = lambda s: self.buffer.write(s.encode('ascii'))
            self.read = lambda: self.buffer.read().decode('ascii')
            self.readline = lambda: self.buffer.readline().decode('ascii')


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip('\r\n')

""" main function"""

if __name__ == '__main__':
    main()
# threading.Thread(target=main).start()