A. Drazil and Factorial

题目连接：

http://codeforces.com/contest/516/problem/A

Description

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.

Sample Input

4

1234

Sample Output

33222

Hint

题意

定义F（x）等于x的每一位的阶乘和。

现在给你一个a，然后让你找到一个最大的x，使得F(x)=F(a)

题解

a的顺序显然是没有关系的，对于每一个数的阶乘，其实只有唯一的对应最长的。

所以直接暴力去置换，然后排个序就好了。

代码

#include<bits/stdc++.h>

using namespace std;

string ans[10]={"","","2","3","322","5","53","7","7222","7332"};

int main()

{

    int n;scanf("%d",&n);

    string s1,s2;cin>>s1;

    for(int i=0;i<s1.size();i++){

        s2+=ans[s1[i]-'0'];

    }

    sort(s2.begin(),s2.end());

    reverse(s2.begin(),s2.end());

    cout<<s2<<endl;

}