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>
#!/usr/bin/env python
#-*- coding:utf-8 -*-

import sys
import math
import random
import operator
from fractions import Fraction, gcd
from decimal import Decimal, getcontext
from itertools import product, permutations, combinations
from Queue import Queue, PriorityQueue
from collections import deque, defaultdict, Counter
getcontext().prec = 100

MOD = 10**9 + 7
INF = float("+inf")

n = int(raw_input())
a = raw_input()

primes = [2, 3, 5, 7]
powers = {p: 0 for p in primes}

for d in a:
    d = int(d)
    for x in xrange(1, d + 1):
        for p in primes:
            while x and x % p == 0:
                powers[p] += 1
                x //= p

# print powers

res = []
for p in primes[::-1]:
    while powers[p]:
        res.append(p)
        # print "drop", p, powers
        for x in xrange(p, 0, -1):
            for p2 in primes:
                while x and x % p2 == 0:
                    powers[p2] -= 1
                    x //= p2
        # print "      ", powers

# print powers
# print res
print "".join(map(str, res))

