Drazil is playing a math game with Varda.

Let's define <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7020b94c48be2ee5b8eeca05f379c8911bb0e7c4.png" style="max-width: 100.0%;max-height: 100.0%;"/> for positive integer *x* as a product of factorials of its digits. For example, <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/6784d861d9a724d0aeddefcb00b7d0c3442ae586.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

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. <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7020b94c48be2ee5b8eeca05f379c8911bb0e7c4.png" style="max-width: 100.0%;max-height: 100.0%;"/> = <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/aa57e017a6c74d06b0a54bc47e3f6990e5af38c1.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

Help friends find such number.
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.
from collections import Counter,defaultdict,deque
#alph = 'abcdefghijklmnopqrstuvwxyz'
#from math import factorial as fact
#import math

tt = 1#int(input())
#total=0
#n = int(input())

#n,m,k = [int(x) for x in input().split()]
for i in range(tt):
   n = int(input())
   s = input()
   d = defaultdict(int)
   for el in s:
      for i in range(2,int(el)+1):
         if i==9:           
            d[3]+=2
         elif i==8:
            d[2]+=3
         elif i==6:
            d[3]+=1
            d[2]+=1
         elif i==4:
            d[2]+=2
         else:
            d[i]+=1
   print(d)
   ans =''
   while d[7]:
      ans+='7'
      d[7]-=1
      d[2]-=4
      d[3]-=2
      d[5]-=1
   while d[5]:
      ans+='5'
      d[5]-=1
      d[2]-=3
      d[3]-=1
   while d[3]:
      ans+='3'
      d[3]-=1
      d[2]-=1
   while d[2]:
      ans+='2'
      d[2]-=1
   print(ans)
      
      
      
