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
import bisect
from collections import Counter,defaultdict
from sys import stdin, stdout
input = stdin.readline
I =lambda:int(input())
M =lambda:map(int,input().split())
LI=lambda:list(map(int,input().split()))
l=I()
n=input()
a=[]
for i in range(l):
    if n[i]=="2":a+=[2]
    elif n[i]=="3":a+=[3]
    elif n[i]=="4":a+=[3,2,2]
    elif n[i]=="5":a+=[5]
    elif n[i]=="6":a+=[5,3]
    elif n[i]=="7":a+=[7]
    elif n[i]=="8":a+=[7,2,2,2]
    elif n[i]=="9":a+=[7,3,3,2]
a.sort(reverse=True)
for i in a:
    print(i,end="")


