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>
d={}
d[2]=[2]
d[3]=[3]
d[4]=[2,2,3]
d[5]=[5]
d[6]=[3,5]
d[7]=[7]
d[8]=[2,2,2,7]
d[9]=[3,3,2,7]
n=int(input())
s=input()
s=int(s)
s=str(s)
ls=[]
for i in s:
	if i!='1' and i!='0':
		lst=d[int(i)]
		for j in lst:
			ls.append(j)
ls.sort(reverse=True)
s=''
for i in ls:
	s=s+str(i)
print(s)