A9837. Drazil and Factorial

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.

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

In the first case,