Drazil is playing a math game with Varda.

Let's define <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7020b94c48be2ee5b8eeca05f379c8911bb0e7c4.png" style="max-width: 100.0%;max-height: 100.0%;"/> for positive integer *x* as a product of factorials of its digits. For example, <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/6784d861d9a724d0aeddefcb00b7d0c3442ae586.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

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. <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7020b94c48be2ee5b8eeca05f379c8911bb0e7c4.png" style="max-width: 100.0%;max-height: 100.0%;"/> = <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/aa57e017a6c74d06b0a54bc47e3f6990e5af38c1.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

Help friends find such number.
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.
def create_number(number):
    digits=[]
    factorials={2:[2],3:[3],4:[3,2,2],5:[5],6:[5,3],7:[7],8:[2,2,2,7],9:[9]}

    while number>0:
        last_digit=number%10
        number=number//10
        if last_digit in factorials:
            cdigits=factorials[last_digit]
            for cdigit in cdigits:
                digits.append(cdigit)
    digits.sort()
    new_number=0
    power=0

    for index in range(len(digits)):
        digit=digits[index]
        new_number=new_number+digit*(10**power)
        power+=1
    result=new_number
    return result


digits_ammount=int(input())
number=int(input())
result=create_number(number)
print(result)