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, 

思路：把数拆一下就是很简单了;

AC代码：

#include <bits/stdc++.h>

using namespace std;

char s[];

int flag[];

int main()

{

    int n;

    scanf("%d",&n);

    memset(flag,,sizeof(flag));

    scanf("%s",s);

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

    {

        if(s[i]=='')

        {

            flag[]+=;

            flag[]+=;

        }

        else if(s[i]=='')

        {

            flag[]+=;

            flag[]+=;

        }

        else if(s[i]=='')

        {

            flag[]+=;

            flag[]+=;

        }

        else if(s[i]=='')

        {

            flag[]+=;

            flag[]+=;

            flag[]+=;

        }

        else flag[s[i]-'']+=;

    }

    for(int i=;i>;i--)

    {

        //cout<<"@"<<flag[i]<<endl;

            while(flag[i])

            {

                printf("%d",i);

                flag[i]-=;

            }

    }

}