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 string
NUMBERS=[]

def factor(x):
    if x == 2 or x==5 or x== 7:
        NUMBERS.append(x)
        return
    else:
       xx = x 
       while x!= 1:
           for i in range(2,4):
               if x%i==0:
                   x = x/i
                   NUMBERS.append(i)
       factor(xx-1)
    return
    


n = int(input())

input_value = input()
num = []
j = 0
for i in range(n):  
    if input_value[i] != '1' and input_value[i] != '0':
        num.append(int(input_value[i]))
        j = j+1
for x in num:
    factor (x)
kkk=NUMBERS

kkk.sort(reverse=True )
for x in NUMBERS:
    
    if x==3:
        kkk.pop()
    



print("".join( map(str, kkk)))


        
        
    
