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.
lst = [0, 0, 0, 0, 0]
n = int(input())
num = input()
for digit in num:
    d = int(digit)
    if d == 2:
        lst[0] += 1
    elif d == 3:
        lst[1] += 1
    elif d == 4:
        lst[0] += 2
        lst[1] += 1
    elif d == 5:
        lst[2] += 1
    elif d == 6:
        lst[1] += 1
        lst[2] += 1
    elif d == 7:
        lst[3] += 1
    elif d == 8:
        lst[0] += 3
        lst[3] += 1
    elif d == 9:
        lst[4] += 1
ret_str = ''
for i in range(5):
    if i == 0:
        ret_str += '2' * lst[i]
    elif i == 1:
        ret_str += '3' * lst[i]
    elif i == 2:
        ret_str += '5' * lst[i]
    elif i == 3:
        ret_str += '7' * lst[i]
    else:
        ret_str += '9' * lst[i]
ret_lst = sorted(ret_str, reverse=True)
print(*ret_lst, sep='')
