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.
from math import factorial

def main():
    n = int(input())
    s = input()
    A = [2, 3, 5, 7]

    reach_fact = 1
    for i in s:
        reach_fact *= factorial(int(i))
    A.sort(reverse=True)
    result = []
    for i in range(n):
        j = i   
        tmp = reach_fact
        cur_res = 0
        while (tmp != 1):
            if (j >= len(A)): break
            if (tmp % factorial(A[j]) == 0 and (A[j] != 1 and A[j] != 0)):
                tmp = tmp / factorial(A[j])
                cur_res = cur_res * 10 + (A[j])
            else:
                j += 1
        if tmp == 1: result.append(cur_res)
    print(max(result))        
if __name__ == '__main__':
    main()