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>
all_premiers_numbers = [2, 3, 5, 7]

# function that returns the decomposition of a number with its factorial
def decompose_number(number):
    if(number in all_premiers_numbers):
        return [number]
    elif number == 4:
        return [3, 2, 2]
    elif number == 6:
        return [3, 5]
    elif number == 8:
        return [2, 2, 2, 7]
    else:
        return [3, 3, 2, 7]

def main():
    n = int(input())
    a = int(input())
    my_list = []
    for chiffre in str(a):
        if((int(chiffre) != 1) and (int(chiffre) != 0)):
            my_list += decompose_number(int(chiffre))

    my_list.sort()
    my_list.reverse()
    final_result = ""
    if(my_list == []):
        print(a)
    else:
        for number in my_list:
            final_result += str(number)
        print(final_result)


main()