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.
def findNum(a):
    numCount = [0]*11
    for num in a:
        for i in range(2, num+1):
            numCount[i] += 1

    # print(numCount)

    for i in range(9, 3, -1):
        shifts = max(0, numCount[i]-numCount[i+1])
        if i == 4:
            numCount[2] += 2*shifts
            numCount[i] -= shifts
        elif i == 6:
            numCount[2] += shifts
            numCount[3] += shifts
            numCount[i] -= shifts
        elif i == 8:
            numCount[2] += 3*shifts
            numCount[i] -= shifts
        elif i == 9:
            numCount[3] += 3*shifts
            numCount[i] -= shifts

    # print(numCount)

    res = []
    for i in range(9, 1, -1):
        for j in range(numCount[i]):
            res.append(str(i))
            for k in range(2, i):
                numCount[k] -= 1
    return ''.join(res)

n = int(input())
a = list(map(int, input()))
print(findNum(a))
