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())
num=input()
i=0
while num[i]==0:
    i+=1
num=num[i:]
mydict={'2':0,'3':0,'4':0,'5':0,'6':0,'7':0,'8':0,'9':0}
for i in num:
    if int(i)>1:
        for j in range(2,int(i)+1):
            mydict[str(j)]+=1
print('7'*mydict['7']+'5'*(mydict['5']-mydict['7'])+'3'*(mydict['9']*2 +mydict['6']+mydict['3']-mydict['5']-mydict['7']*2)+'2'*(mydict['8']*3+mydict['6']+mydict['4']*2+mydict['2']-mydict['7']*4-mydict['5']*3-mydict['3']))