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 F(a):
    ans=1
    for i in a:
        ans *= fact(int(i))

    return ans


def fact(n):
    if n==0:
        return 1
    ans=1
    while n>= 1:
        ans *= n
        n -= 1
    return ans

n=int(raw_input())
a=raw_input()

largest_num=[]

for i in a:
    if int(i)>1:
        if i=='4':
            largest_num.append(2)
            largest_num.append(2)
            largest_num.append(3)
        elif i=='6':
            largest_num.append(3)
            largest_num.append(5)
        elif i=='8':
            largest_num.append(2)
            largest_num.append(2)
            largest_num.append(2)
            largest_num.append(7)
        elif i=='9':
            largest_num.append(3)
            largest_num.append(3)
            largest_num.append(2)
            largest_num.append(7)
        else:
            largest_num.append(int(i))

largest_num.sort(reverse=True)
num=''

for i in largest_num:
    num += str(i)

print num






