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 fact(num):
	f=1
	while (num>0):
		f=f*num
		num-=1
	return f

n=int(input())
a=int(input())

d={"0":0,"1":0,"2":2,"3":3,"4":322,"5":5,"6":53,"7":7,"8":7222,"9":7332}

sa=str(a)
sans=""
for i in sa:
	num=d[i]
	if (num!=0):
		sans+=str(num)
#print(sans)
arr=[]
for i in sans:
	arr.append(i)

for i in range(len(arr)):
	for j in range(len(arr)):
		if (ord(arr[j])>ord(arr[i])):
			arr[j],arr[i]=arr[i],arr[j]

arr.sort(reverse=True)
ans=0
for i in arr:
	ans=ans*10+int(i)
print(ans)