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 functools
import heapq as hp
import collections
import bisect
import math


def unpack(func=int):
    return map(func, input().split())


def l_unpack(func=int):
    """list unpack"""
    return list(map(func, input().split()))


def s_unpack(func=int, rev=False):
    """sorted list unpack"""
    return sorted(map(func, input().split()), reverse=rev)


def ml_unpack(n):  # multiple line unpack
    """list of n integers passed on n line, one on each"""
    return [int(input()) for i in range(n)]


def range_n():
    return range(int(input()))


def getint():
    return int(input())


def counter(a):
    d = {}
    for x in a:
        if x in d:
            d[x] += 1
        else:
            d[x] = 1
    return d


def main():
    n = getint()
    a = input()
    ans = []
    for e in a:
        if e in {'0', '1'}:
            continue
        if e == '4':
            ans.append(2)
            ans.append(2)
            ans.append(3)
        elif e == '6':
            ans.append(3)
            ans.append(5)
        elif e == '8':
            ans.append(2)
            ans.append(2)
            ans.append(2)
            ans.append(7)
        elif e == '9':
            ans.append(3)
            ans.append(3)
            ans.append(2)
            ans.append(7)
        else:
            ans.append(int(e))
    ans.sort(reverse=True)
    print(*ans, sep='')


main()
