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 1
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 2
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 2
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 250
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 3
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 7
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 5
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 2
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 3
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 2
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 2
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 3
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 15
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 3
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 2
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 2
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 2
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 2
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"""
// Author : snape_here - Susanta Mukherjee
     
"""
 
from __future__ import division, print_function
 
import os,sys
from io import BytesIO, IOBase
 
if sys.version_info[0] < 3:
    from __builtin__ import xrange as range
    from future_builtins import ascii, filter, hex, map, oct, zip
 
 
def ii(): return int(input())
def si(): return input()
def mi(): return map(int,input().split())
def li(): return list(mi())
 
 
def gcd(x, y):
    while y:
        x, y = y, x % y
    return x
    
 
def read():
    sys.stdin = open('input.txt', 'r')  
    sys.stdout = open('output.txt', 'w') 
 
 
import math

from itertools import permutations

mod=100000007 

# Python3 code to find largest prime 
# factor of number 
import math 
  
# A function to find largest prime factor 
def maxPrimeFactors (n): 
      
    # Initialize the maximum prime factor 
    # variable with the lowest one 
    maxPrime = -1
      
    # Print the number of 2s that divide n 
    while n % 2 == 0: 
        maxPrime = 2
        n >>= 1     # equivalent to n /= 2 
          
    # n must be odd at this point,  
    # thus skip the even numbers and  
    # iterate only for odd integers 
    for i in range(3, int(math.sqrt(n)) + 1, 2): 
        while n % i == 0: 
            maxPrime = i 
            n = n / i 
      
    # This condition is to handle the  
    # case when n is a prime number  
    # greater than 2 
    if n > 2: 
        maxPrime = n 

    return maxPrime

# Python3 program to find the most 
# frequent element in an array. 
import math as mt 

def mostFrequent(arr, n): 
  
    # Sort the array 
    arr.sort() 
  
    # find the max frequency using 
    # linear traversal 
    max_count = 1; res = arr[0]; curr_count = 1
      
    for i in range(1, n):  
        if (arr[i] == arr[i - 1]): 
            curr_count += 1
              
        else : 
            if (curr_count > max_count):  
                max_count = curr_count 
                res = arr[i - 1] 
              
            curr_count = 1
      
    # If last element is most frequent 
    if (curr_count > max_count): 
      
        max_count = curr_count 
        res = arr[n - 1] 
      
    return res 



def main():

    k=ii()
    s=si()
    h=[0]*26 
    for i in range(len(s)):
        h[ord(s[i])-97]+=1 
    for i in range(26):
        if h[i]%k!=0:
            print(-1)
            exit()
    x=[0]*26 
    for i in range(26):
        x[i]=h[i]//k
    ans=""
    for i in range(k):
        for i in range(26):
            if h[i]:
                ans+=x[i]*(chr(i+97))
                h[i]-=x[i]
    print(ans)
        

# region fastio#
 
BUFSIZE = 8192
 
 
class FastIO(IOBase):
    newlines = 0
 
    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None
 
    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()
 
    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()
 
    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)
 
 
class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        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")
 
 
def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", "\n"))
    if kwargs.pop("flush", False):
        file.flush()
 
 
if sys.version_info[0] < 3:
    sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
else:
    sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
 
input = lambda: sys.stdin.readline().rstrip("\r\n")
 
# endregion
 
 
if __name__ == "__main__":
    #read()
    main() 
#Comment read()
