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 fac(x):
    if x==0:
        return 1
    else:
        s=1
        for i in range(n):
            s=s*i
        return s
    
n=int(input())
a=input()
d={}
lis=[]
d[4]=[2,2,3]
d[6]=[5,3]
d[8]=[2,2,2,7]
d[9]=[3,3,2,7]
for k in a:
    k=int(k)
    if k in d:
        lis.extend(d[k])
    elif k>1:
        lis.append(k)
lis.sort()
for u in lis[::-1]:
    print(u,end='')
