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 fact(x):
    ans = 1
    for i in range(2, x):
        ans *= i
    return ans

n = int(input())
a = list(map(int, list(input())))
data = {}
for i in range(n):
    for j in range(2, a[i] + 1):
        try:
            data[j] += 1
        except:
            data[j] = 1

try:
    m = data[4] * 2
    del(data[4])
    data[2] += m
except:
    pass

try:
    m = data[6]
    del(data[6])
    data[2] += m
    data[3] += m
except:
    pass

try:
    m = data[8] * 4
    del(data[8])
    data[2] += m
except:
    pass

try:
    m = data[9] * 2
    del(data[9])
    data[3] += m
except:
    pass

#print(data)

for i in range(9, 1, -1):
    try:
        k = data[i]
    except:
        continue
    while k != 0:
        for j in range(2, i + 1):
            try:
                data[j] -= 1
            except:
                if j == 4:
                    data[2] -= 2
                elif j == 6:
                    data[2] -= 1
                    data[3] -= 1
                elif j == 8:
                    data[2] -= 4
                else:
                    data[3] -= 2
        print(i, end="")
        k -= 1
    del(data[i])