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 -*-

import math
import collections
import bisect
import heapq
import time
import random
import itertools
import sys

"""
created by shhuan at 2017/11/24 18:49

"""


N = int(input())

S = input()

count = [0] * 10

for v in [int(v) for v in S]:
    if v == 4:
        count[3] += 1
        count[2] += 2
    elif v == 8:
        count[2] += 3
        count[7] += 1
    elif v == 6:
        count[5] += 1
        count[3] += 1
    elif v == 9:
        count[2] += 1
        count[3] += 2
        count[7] += 1
    else:
        count[v] += 1

ans = ""
for i in range(9, 1, -1):
    ans += str(i) * count[i]
print(ans)