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 bisect
from collections import defaultdict
from collections import deque
import math
import re

def ni():
    return int(raw_input())

def nis():
    return map(int, raw_input().split())

def si():
    return raw_input()

def sis():
    return raw_input().split()

vals = [[0], [1], [2], [3], [2, 2, 3], [5], [3, 5], [7], [2, 2, 2, 7], [2, 3, 3, 7]]

n = ni()
a = filter(lambda x: x > 1, map(int, list(si())))

ans = []
for x in a:
    ans.extend(vals[x])

ans.sort(reverse=True)

print ''.join(map(str, ans))