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 = []
two, three, five, sev = 0,0,0,0
for i in range(len(s)):
    for a in range(2, int(s[i])+1):
        while(a%2==0):
            vls.append(2)
            a//=2
        while(a%3==0):
            vls.append(3)
            a//=3
        if(a!= 1):
            vls.append(a)
mrk = [1 for i in range(len(vls))]
vls = sorted(vls, key = lambda x:int(x))
for i in range(len(vls)):
    if(vls[i]==3):
        two+=1
    if(vls[i]==5):
        two+=3
        three+=1
    if(vls[i]==7):
        two+=4
        three+=2
        five+=1
for i in range(len(vls)):
    if(vls[i]==2 and two):
        mrk[i]=0
        two-=1
    if(vls[i]==3 and three):
        mrk[i]=0
        three-=1
    if(vls[i]==5 and five):
        mrk[i]=0
        five-=1
    if(vls[i]==7 and sev):
        mrk[i]=0
        sev-=1
ans = []
for i in range(len(vls)-1, -1, -1):
    if(mrk[i]):
        ans.append(str(vls[i]))
print(''.join(ans))