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.
# Problem D
import sys, functools, string
input = lambda: sys.stdin.readline()[:-1]
get_int = lambda: int(input())
get_int_list = lambda: list(map(int,input().split()))

p = {1:[0,0,0,0],
    2:[1,0,0,0],
     3:[1,1,0,0],
     4:[3,1,0,0],
     5:[3,1,1,0],
     6:[4,2,1,0],
     7:[4,2,1,1],
     8:[7,2,1,1],
     9:[7,4,1,1]}

def al(a,b):
    return [a[i]+b[i] for i in range(len(a))]
def sl(a,b):
    return [a[i]-b[i] for i in range(len(a))]
def solve(a):
    remain = [0,0,0,0]
    s = str(a)
    for char in s:
        remain = al(remain,p[int(char)])
    ans = ''
    while remain[-1]:
        ans += '7'
        remain = sl(remain,p[7])
    while remain[-2]:
        ans +='5'
        remain = sl(remain,p[5])
    while remain[-3]:
        ans += '3'
        remain = sl(remain,p[3])
    while remain[0]:
        ans += '2'
        remain = sl(remain,p[2])
    print(ans)

n = get_int()
a = get_int()
solve(a)
