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.
n = int(input())

a = input()

counts = {
    '2': 0,
    '3': 0,
    '5': 0,
    '7': 0
}
for c in a:
    c = int(c)
    if c == 2:
        counts['2'] += 1
    if c == 3:
        counts['3'] += 1
    if c == 4:
        counts['3'] += 1
        counts['2'] += 3
    if c == 5:
        counts['5'] += 1
    if c == 6:
        counts['3'] += 2
        counts['2'] += 4
        counts['5'] += 1
    if c == 7:
        counts['7'] += 1
        counts['3'] += 2
        counts['2'] += 4
        counts['5'] += 1
    if c == 8:
        counts['2'] += 3
        counts['7'] += 1
        counts['3'] += 2
        counts['2'] += 4
        counts['5'] += 1
    if c == 9:
        counts['3'] += 2
        counts['2'] += 3
        counts['7'] += 1
        counts['3'] += 2
        counts['2'] += 4
        counts['5'] += 1

ans = ""
ans += '7' * counts['7']
ans += '5' * counts['5']
ans += '3' * counts['3']
ans += '2' * counts['2']
print(ans)
