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>
def fa(n):
	if n==0:
		return 1
	else:
		return n*fa(n-1)
n=int(input())
a=input()
_as=[int(i) for i in a]
_fa=1
for i in _as:
	_fa*=fa(i)
# print(_fa)
di={2:[2],3:[3],4:[3,2,2],5:[5],6:[3,5],7:[7],8:[2,2,2,7],9:[3,3,2,7]}
xs=[]
for i in _as:
	try:
		xs+=di[i]
	except KeyError:
		pass

xs.sort()
s=''
for i in range(len(xs)-1,-1,-1):
	s+=str(xs[i])
print(s)