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
#n,m=map(int,input().split())
from collections import Counter
#for i in range(n):
import math
#for _ in range(int(input())):
#n = int(input())
#for _ in range(int(input())):
#n = int(input())
import bisect
'''for _ in range(int(input())):

    n=int(input())

    n,k=map(int, input().split())

    arr = list(map(int, input().split()))'''
#n, m, k = [int(x) for x in input().split()]
#n,m=map(int,input().split())
n=int(input())
s=list(input())
#s.sort(reverse=True)
d={}
d[2]=2
d[3]=3
d[4]=322
d[5]=5
d[6]=53
d[7]=7
d[8]=7222
d[9]=7332
ans=""
for i in s:
    if i!="0" and i!="1":
        ans+=str(d[int(i)])
ans=list(ans)
print("".join(sorted(ans))[::-1])


