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.

# Online Python - IDE, Editor, Compiler, Interpreter
import os
import statistics

if __name__ == "__main__":
    n = int(input())
    chuoi = input()
    
    A = []
    
    for i in range(0, 10):
        A.append(0)
    
    for i in range(0,n):
        A[int(chuoi[i])] += 1
        
    A[7] += A[8] + A[9]
    A[5] += A[6]
    A[3] += A[6] + A[4] + 2*A[9]
    A[2] += 2*A[4] + 3*A[8] + A[9]
    A[9] = 0
    A[8] = 0
    A[6] = 0
    A[4] = 0
    
    result = ""
    for i in range(9, 1, -1):
        while A[i] > 0:
            result += str(i)
            A[i] -= 1
        
    print(result)
