Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

First, they choose a decimal number a consisting of n digits that contains at least one digit larger than 1. This number may possibly start with leading zeroes. Then they should find maximum positive number x satisfying following two conditions:

1. x doesn't contain neither digit 0 nor digit 1.

2. <image> = <image>.

Help friends find such number.

Input

The first line contains an integer n (1 ≤ n ≤ 15) — the number of digits in a.

The second line contains n digits of a. There is at least one digit in a that is larger than 1. Number a may possibly contain leading zeroes.

Output

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
'''
Created on Feb 21, 2015

@author: link
'''


import sys

def preprocess(s):
    return [int(x) for x in s if x!="0" and x!="1"]
n = input()
n = input()
#print(n)
#print(preprocess(n))
buffer = preprocess(n)
buffer.sort(reverse = True)
#print(buffer)
f = {2:2,
    3:3,
    4:322,
    5:5,
    6:53,
    7:7,
    8:7222,
    9:7332}
res = [str(f[x]) for x in buffer]
s = ""
for i in res:
    s += i
s = list(s)
res = [int(x) for x in s]
res.sort(reverse = True)
ans = ""
for i in res:ans+=str(i)
print(ans)


