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

def factor(n):
	if n <= 3 or n == 5 or n == 7:
		return [n]
	if n == 4:
		return [2,2]
	if n == 6:
		return [2,3]
	if n == 8:
		return [2,2,2]
	if n == 9:
		return [3,3]
		
def remove_factor(l, elem):
	for i in range(2,elem+1):
		for j in factor(i):
			l.remove(j)
	return l

def main():
	tmp =  input()
	input_num = raw_input()
	
	l = []
	for digit in str(input_num):
		nums = [x for x in range(2,int(digit)+1)]
		factors = [factor(x) for x in nums]
		
		for factor_list in factors:
			l.extend(factor_list)
	
	l.sort()
	l.reverse()
	#print l
	out = []
	while len(l) > 0:
		elem = l[0]
		l = remove_factor(l, elem)
		out.append(elem)
		
	print ''.join([str(x) for x in out])
	





main()
