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>
# -*- coding: utf-8 -*-
"""
Created on Tue Jun 30 18:49:08 2015

@author: l.maria
"""

n = input()

l1 = map(int,raw_input())

l2 = []
   
for digit in l1:
    
    if digit == 4:
        
        l2.extend([2,2,3])
        
    elif digit == 6:
            
        l2.extend([3,5])
        
    elif digit == 8:
            
        l2.extend([2,2,2,7])
        
    elif digit == 9:
            
        l2.extend([2,3,3,7])

    else:

        l2.append(digit)
        
l2.sort(reverse=True)

print ''.join([str(x) for x in l2 if x > 1])