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>
# cook your code here
# Prime Factorisation of 0 to 9
facts = [ [], [], [2], [3], [2, 2], 
          [5], [2, 3], [7], [2, 2, 2], [3, 3]]

nums = {}
for i in xrange(2, 10):
    nums[i] = 0

n = int(raw_input())
num = raw_input()
new = ""

for x in num :
    if x != "1" and x != "0" :
        digit = int(x) 
        while digit > 1 :
            for factor in facts[digit]:
                nums[factor] += 1
                
            digit -= 1 
    
for i in xrange(9, 1, -1):
    new += str(i) * nums[i] 
    cnt = nums[i] 
    digit = i - 1
    while digit > 1 :
        for x in facts[digit] :
            nums[x] -= cnt 
        digit -= 1


print new 