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>
from math import factorial
digs = input()
nma = str(raw_input())
primes = {2:0, 3:0, 5:0, 7:0}
p_no = [7,5,3,2]
facts = {2:2, 3:6, 5:120, 7:7*720}

a = 1
for d in nma:
	a = a*factorial(int(d))

for p in p_no:  
	while a > 0 and a%p == 0:
		a = a/facts[p]
		primes[p] = primes[p] + 1

num = []
for p in p_no:
	num.extend([p] * primes[p])
nums = [str(x) for x in num]
print "".join(nums)
	

