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 -*-
#ᕕ┌◕ᗜ◕┐ᕗ HELLO HELLO HELLO ᕕ┌◕ᗜ◕┐ᕗ

def factorial(n):
    if n == 0 or n == 1:
        return 1
    if n == 2:
        return 2
    if n == 3:
        return 6
    if n == 4:
        return 24
    if n == 5:
        return 120
    if n == 6:
        return 720
    if n == 7:
        return 5040
    if n == 8:
        return 40320
    if n == 9:
        return 362880

n = int(raw_input())
a = raw_input()
p = 1
for i in a:
    p *= factorial(int(i))
s = ""
while p%7 == 0:
    s = s + "7"
    p /= 5040
while p%5 == 0:
    s = s + "5"
    p /= 120
while p%3 == 0:
    s = s + "3"
    p /= 6
while p%2 == 0:
    s = s + "2"
    p /= 2
print s
