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={
    0:[],
    1:[],
    2:[2],
    3:[3],
    4:[3,2,2],
    5:[5],
    6:[5,3],
    7:[7],
    8:[7,2,2,2],
    9:[7,3,3,2],
    }
n=input()
s=raw_input()
a=[]
for i in s:
    a+=d[int(i)]
a.sort(reverse=True)
ans=""
for i in a:
    ans+=str(i)
print ans