human
Drazil is playing a math game with Varda.

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

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.  = .

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,
assistant
#Here is Python program to find maximum positive number x satisfying following two conditions:
.

from sys import stdin, gettrace

if not gettrace():
    def input():
        return next(stdin)[:-1]

# def input():
#    return stdin.buffer.readline()

def main():
    input()
    aa = input()
    digits = []
    for a in aa:
        if a == '2':
            digits.append('2')
        elif a == '3':
            digits.append('3')
        elif a == '4':
            digits += ('2','2','3')
        elif a == '5':
            digits.append('5')
        elif a == '6':
            digits += ('3', '5')
        elif a == '7':
            digits.append('7')
        elif a == '8':
            digits += ('2','2','2', '7')
        elif a == '9':
            digits += ('3', '3', '2', '7')
    digits.sort(reverse=True)
    print(''.join(digits))

if __name__ == "__main__":
    main()