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

def pt(n):
    for i in range(1, 5):
        if(n==(2**i)):
            return i
    return False
n=  int(input())
s = str(int((input())))
vls = []
for i in range(n):
    for c in range(2, int(s[i])+1):
        while(c%2==0):
            vls.append('2')
            c//=2
        if(c!= 1):
            vls.append(str(c))

vls = sorted(vls, key = lambda x:int(x))
mrk = [1 for i in range(len(vls))]
pnt = len(vls)-1
ans = []
while(1 in mrk):
    pnt = len(vls)-1
    while(mrk[pnt]==0):
        pnt-=1
    no= int(vls[pnt])-1
    mrk[pnt] = 0
    ans.append(vls[pnt])
    pnt-=1
    while(pnt> 0):
        if(pt(no)):
            tot = pt(no)
            np= int(pnt)
            while(tot> 0):
                if(mrk[np]==1 and vls[np]=='2'):
                    tot-=1
                    mrk[np]=0
                np-=1
            no-=1
        elif(int(vls[pnt])==no and mrk[pnt]):
            mrk[pnt]=0
            no-=1
        pnt-=1
print(''.join(ans))