Drazil and Factorial

题意翻译

题目描述 Drazil正在和Varda一起玩数学游戏。 让我们定义正整数x作为其数字的阶乘的乘积。例如,F(135)=1!*3!*5!=720。 首先,他们选择一个十进制数a,a是一个由n个数字组成的数。此数字可能以前导零开头。然后他们要找到最大正数x,x满足以下两个条件: 1.x不包含任何数字0和数字1。 2.F(x)=F(a)。 帮朋友找到这样的号码。 输入输出格式 输入格式: 第一行包含一个整数n(1<=n<=15)。 第二行包含一个长度n的数字a。a至少有一位数字。数字a可能包含前导零。 输出格式: 输出满足上述条件的最大可能整数。在这个数字十进制表示中应该没有零和1。

题目描述

Drazil is playing a math game with Varda. Let's define ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF515C/d6d82501d6896204eb129fda0fbb874a4dca8b3d.png) for positive integer $ x $ as a product of factorials of its digits. For example, ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF515C/924b94e6754519a09747f51e1aee23c2150a9aae.png). 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\. ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF515C/d6d82501d6896204eb129fda0fbb874a4dca8b3d.png) = ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF515C/89af95f2102ccc78e5791a11cc6627eae6cfc66b.png). Help friends find such number.

输入输出格式

输入格式


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.

输出格式


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

输入输出样例

输入样例 #1

4
1234

输出样例 #1

33222

输入样例 #2

3
555

输出样例 #2

555

说明

In the first case, ![](https://cdn.luogu.com.cn/upload/vjudge_pic/CF515C/03f0e4ffa692ff76d804fd5bac30e112277eb665.png)