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.
import math

n = int(input())
s = str(int(input()))
vls = []
nos =''
for i in range(len(s)):
    if(s[i]=='2'):
        nos+='2'
    if(s[i]=='3'):
        nos+='3'
    if(s[i]=='4'):
        nos+='322'
    if(s[i]=='5'):
        nos+='5'
    if(s[i]=='6'):
        nos+='53'
    if(s[i]=='7'):
        nos+='7'
    if(s[i]=='8'):
        nos+='7222'
    elif(s[i]=='9'):
        nos+='7332'
ans = []
for i in range(len(nos)):
    ans.append(int(nos[i]))
ans= sorted(ans, reverse= True)
sans = ''
for i in range(len(nos)):
    sans+=str(ans[i])
print(sans)