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.
def primefactors(x):
    d={2:0,3:0,5:0,7:0}
    l=[2,3,5,7]
    for y in l:
        while x%y==0:
            d[y]+=1
            x//=y
    return d
import sys
input=sys.stdin.readline
from math import factorial
n=int(input())
a=input().rstrip()
num=1
for x in a:
    num*=factorial(int(x))

d=primefactors(num)
ans=''
s7=s5=s3=s2=''
s7=d[7]*'7'
ans+=s7
d[2]-=d[7]*4
d[3]-=d[7]*2
d[5]-=d[7]
s5=d[5]*'5'
ans+=s5
d[2]-=d[5]*3
d[3]-=d[5]
s3=d[3]*'3'
ans+=s3
d[2]-=d[3]
s2=d[2]*'2'
ans+=s2
print(ans)