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

def in_int():
    '''
    Read input string as int
    '''
    return (int(input()))

def in_int_space():
    '''
    Read space separated numbers as list of int
    '''
    return (list(map(int,input().split())))

def in_int_line(n):
    '''
    Read line separated input as list of int
    '''
    list = []
    for i in range(n):
        s = input()
        list.append(int(s[:len(s)-1]))
    return list

def in_str():
    '''Read string'''
    s = input()
    return s[:len(s)-1]

def in_str_arr():
    '''
    Read String as Char array
    '''
    s = input()
    return (list(s[:len(s)-1]))

def in_str_space():
    return input().split()

def in_str_line(n):
    list = []
    for i in range(n):
        s = input()
        list.append(s[:len(s)-1])
    return list
n = in_int() 
s = in_str() 
res = [] 
for a in s: 
    if a in ['0', '1']:
        continue 
    elif a in ["2", "3", "5", "7", "9"]:
        res.append(int(a))
    elif a == '4':
        res.extend([3,2,2]) 
    elif a == '6':
        res.extend([5,3]) 
    elif a == '8': 
        res.extend([7,2,2,2]) 
res.sort(reverse = True) 

print(int("".join(list(map(str,res)))))