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.
import math
numdigits = int(input())
arrstring = input()
arr = [int(element) for element in arrstring]
product = 1
factorialfactors = {2: 0, 3: 0, 5: 0, 7: 0}
divisors = [2, 3, 5, 7]

for digit in arr:
    toadd = math.factorial(digit)
    for divi in reversed(divisors):
        while toadd % math.factorial(divi) == 0:
            factorialfactors[divi] += 1
            toadd /= math.factorial(divi)




finalanswer = []

for x in divisors:
    for j in range(factorialfactors[x]):
        finalanswer.append(x)

finalanswer.reverse()
for x in range(len(finalanswer)):
    print(finalanswer[x], end='')

print()