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.
num = int(input())
a = list(map(int,list(input())))
array = []
for i in a:
    if i > 1:
        for k in range(1, i+1):
            if k > 1:
                if k == 4:
                    array.append(2)
                    array.append(2)
                elif k == 6:
                    array.append(3)
                    array.append(2)
                elif k == 8:
                    array.append(2)
                    array.append(2)
                    array.append(2)
                elif k == 9:
                    array.append(3)
                    array.append(3)
                else:
                    array.append(k)
res = ''
while array:
    maximum = max(array)
    res += str(maximum)
    for i in range(maximum, 1, -1):
        if i == 4:
            array.remove(2)
            array.remove(2)
        elif i == 6:
            array.remove(2)
            array.remove(3)
        elif i == 8:
            array.remove(2)
            array.remove(2)
            array.remove(2)
        elif i == 9:
            array.remove(3)
            array.remove(3)
        else:
            array.remove(i)
print(res)
    
