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, 

题意 给出数x，得出x各位数阶乘的乘积；求得出的各位数乘积和与x得出的各位数阶乘的乘积相等的最大数

先打表ch[i] F[i]=F[p]最大值p，排序，反转

#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

int main(){

    int n;

    scanf("%d",&n);

    string str;

    cin>>str;

    string str1 = "";

    string ch[]={"","","","","","","","","",""};

    for(int i = ; i < n; i++){

        str1 += ch[str[i]-''];

    }

    sort(str1.begin(),str1.end());

    reverse(str1.begin(),str1.end());

    cout<<str1<<endl;

    return ;

}