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>
'''input
3
92
'''
# connected components
from sys import stdin
from collections import defaultdict
import sys

sys.setrecursionlimit(15000)
	
# main starts
n = int(stdin.readline().strip())
string = list(stdin.readline().strip())
mydict  = []
for i in string:
	if i == '0' or i == '1':
		continue
	else:
		num = int(i)
		if num in [2, 3, 5, 7]:
			mydict.append(num)
		else:
			if num == 4:
				mydict.append(3)
				mydict.append(2)
				mydict.append(2)
			if num == 6:
				mydict.append(5)
				mydict.append(3)
			if num == 8:
				mydict.append(7)
				mydict.append(2)
				mydict.append(2)
				mydict.append(2)
			if num == 9:
				mydict.append(7)
				mydict.append(3)
				mydict.append(3)
				mydict.append(2)
mydict.sort(reverse = True)
for i in mydict:
	print(i, end = '')