Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

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. <image> = <image>.

Help friends find such number.

Input

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.

Output

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
"""
Codeforces Contest 292 Div 1 Problem A

Author  : chaotic_iak
Language: Python 3.4.2
"""

################################################### SOLUTION

def main():
    n, = read()
    a = read(0)
    digits = []
    for i in a:
        if i == "0" or i == "1": continue
        if i == "2": digits.append(2)
        if i == "3": digits.append(3)
        if i == "4": digits.extend([3,2,2])
        if i == "5": digits.append(5)
        if i == "6": digits.extend([5,3])
        if i == "7": digits.append(7)
        if i == "8": digits.extend([7,2,2,2])
        if i == "9": digits.extend([7,3,3,2])
    digits.sort(reverse=True)
    print("".join(str(i) for i in digits))


	
#################################################### HELPERS



def read(mode=2):
    # 0: String
    # 1: List of strings
    # 2: List of integers
    inputs = input().strip()
    if mode == 0: return inputs
    if mode == 1: return inputs.split()
    if mode == 2: return list(map(int, inputs.split()))

def write(s="\n"):
    if s is None: s = ""
    if isinstance(s, list): s = " ".join(map(str, s))
    s = str(s)
    print(s, end="")

write(main())