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>
#!/usr/bin/python
# -*- coding: utf-8 -*-
"""One line explanation of c.py.

More explanations of c.py."""

import sys


def main(argv):
    _ = sys.stdin.readline()
    digits = sys.stdin.readline().strip()
    result = ''
    table = ['', '', '2', '3', '223', '5', '35', '7', '7222', '7332']
    for c in digits:
        result += table[ord(c) - ord('0')]
    sys.stdout.write(''.join(reversed(sorted(result))) + '\n')

if __name__ == '__main__':
    main(sys.argv)
