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 ii(): return int(input())
def fi(): return float(input())
def si(): return input()
def mi(): return map(int,input().split())
def li(): return list(mi())

n=ii()
s=si()
x=""
for i in s:
    if int(i)>1:
        i=str(i)
        if i=='4':
            x+="322"
        elif i=='6':
            x+="53"
        elif i=='8':
            x+="7222"
        elif i=='9':
            x+="7332"
        else:
            x+=str(i)
    else:
        continue
l=[]
for i in x:
    l.append(i)
l.sort(reverse=True)
print("".join(l))