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 sys

input = sys.stdin.readline

factorials = [0, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880]


#n, k = map(int, input().split())

n = int(input())
a = list(map(int, list(input().strip())))
# s2 = list(map(int, list(input().strip())))
# print(s1)

b = [1]

s = set()
sm = 1
tabl = []
for i in range(n):
    if a[i] > 1:
        sm *= factorials[a[i]]

ind = [0]*10
ans = [0]*10
#print(sm)
while sm > 1:
    for i in range(2, 10):
        #print(factorials[i])
        if sm % i == 0:
            ans[i] += 1
            sm = sm / i
            #print(sm)
#print(ans)
for i in range(len(ans) - 1, 2, -1):
    if i % 2 == 0:
        if ans[i] != 0:
            if i == 8:
                ans[2] += 3*ans[i]
                ans[8] = 0
            if i == 6:

                ans[2] += ans[i]
                ans[3] += ans[i]
                ans[6] = 0
            if i == 4:
                ans[2] += 2*ans[i]
                ans[4] = 0

    else:
        if ans[i] != 0:
            for j in range(2, i):
                ans[j] -= ans[i]
    #print(ans)
for i in range(len(ans) - 1, 1, -1):
    if ans[i] != 0:
        print(str(i) * ans[i], end="")

#print(ans)











