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 itertools, math, random, re, string, sys
from bisect import *
from collections import *
from decimal import *
from fractions import *
from itertools import combinations, permutations, product
from math import ceil, exp, log, sqrt
from Queue import *
getcontext().prec = 100
sys.setrecursionlimit(100000)
MOD = 10 ** 9 + 7
INF = float('+inf')

fs = [1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880]

def factors(n):
    return set(reduce(list.__add__, ([i] for i in fs if n % i == 0)))

def F(s):
    return reduce(lambda r, x: r * x, [fs[i] for i in s], 1)

n = input()
a = raw_input()
a = list([int(x) for x in a if x != '1' and x != '0'])

for i in xrange(len(a)):
    if a[i] == 4:
        a[i] = 3
        a += [2, 2]
    elif a[i] == 6:
        a[i] = 5
        a.append(3)
    elif a[i] == 8:
        a[i] = 7
        a += [2, 2, 2]
    elif a[i] == 9:
        a[i] = 7
        a += [3, 3, 2]
print ''.join(sorted(map(str, a), reverse=True))
