Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

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. <image> = <image>.

Help friends find such number.

Input

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.

Output

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
import math,sys
from collections import Counter, defaultdict, deque
from sys import stdin, stdout
input = stdin.readline
lili=lambda:list(map(int,sys.stdin.readlines()))
li = lambda:list(map(int,input().split()))
#for deque append(),pop(),appendleft(),popleft(),count()
I=lambda:int(input())
S=lambda:input()

n=I()
s=S()
a=[]
for j in range(0,n):
    i=s[j]
    if(i=='4'):
        a.append(3)
        a.append(2)
        a.append(2)
    elif(i=='6'):
        a.append(5)
        a.append(3)
    elif(i=='8'):
        a.append(7)
        a.append(2)
        a.append(2)
        a.append(2)
    elif(i=='9'):
        a.append(7)
        a.append(2)
        a.append(3)
        a.append(3)
    elif(i!='0' and i!='1'):
        a.append(int(i))
a.sort(reverse=True)
print("".join(map(str,a)))
    
    