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 sys
from math import *
in_file = sys.stdin
#in_file = open("test.txt" , 'r')

def read_ints():
	global in_file

	lister = map(int , in_file.readline().strip().split() )
	if len(lister) == 1 : return lister[0]
	return lister

factorized = [ [0,0,0,0], [0,0,0,0], [1,0,0,0], [1,1,0,0], [3,1,0,0], [3,1,1,0] , [4,2,1,0], [4,2,1,1], [7,2,1,1], [7,4,1,1]       ]



n = read_ints()
a = read_ints()
#print n,a



totaler = [0,0,0,0]

#print a
for num in str(a):
	num = int(num)

	if (num > 1):
		for j in range(4):
			totaler[j] += factorized[num][j]

nums = []
counter = 0;
while totaler != [0,0,0,0]:
	#print totaler
	highest = 0
	for j in range(4):
		if totaler[j]:
			highest = j

	if (highest == 0): highest = 2
	elif highest == 1: highest = 3
	elif highest == 2: highest = 5
	elif highest == 3: highest = 7

	nums.append(str(highest))
	for j in range(4):
		totaler[j] -= factorized[highest][j]
	counter += 1
	#if (counter > 25): break

print "".join(nums)