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 os, sys, bisect, copy
from collections import defaultdict, Counter, deque
from functools import lru_cache   #use @lru_cache(None)
if os.path.exists('in.txt'): sys.stdin=open('in.txt','r')
if os.path.exists('out.txt'): sys.stdout=open('out.txt', 'w')
#
def input(): return sys.stdin.readline()
def mapi(arg=0): return map(int if arg==0 else str,input().split())
#------------------------------------------------------------------

n = int(input())
a = input().strip()
freq = defaultdict(int)
for i in a:
    tmp = int(i)
    if tmp<=1:
        continue
    if tmp ==4:
        freq[2]+=2
        freq[3]+=1
    elif tmp == 6:
        freq[3]+=1
        freq[5]+=1
    elif tmp==8:
        freq[2]+=3
        freq[7]+=1
    elif tmp==9:
        freq[3]+=2
        freq[7]+=1
        freq[2]+=1
    else:
        freq[tmp]+=1
res = []
for i in range(9,1,-1):
    for j in range(freq[i]):
        res.append(str(i))
print("".join(res))

