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.
n=int(input())
digit=int(input())
l=[]
s=str(digit)
res=[]
for i in s:
    if(i=='2'):
        res.append('2')
    if(i=='3'):
        res.append('3')
    if(i=='4'):
        res.append('2')
        res.append('2')
        res.append('3')
    if(i=='5'):
        res.append('5')
    if(i=='6'):
        res.append('3')
        res.append('5')
    if(i=='7'):
        res.append('7')
    if(i=='7'):
        res.append('7')
        res.append('2')
        res.append('2')
        res.append('2')
    if(i=='8'):
        res.append('7')
        res.append('3')
        res.append('3')
        res.append('2')
res.sort()
res.reverse()
print(''.join(res))
