Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

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. <image> = <image>.

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.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
import java.util.*;

public class fact
{
  public static void main(String[] args)
  {
    Scanner scan=new Scanner(System.in);
    int n=scan.nextInt();
    int m=n;
    long b=scan.nextLong();
    long []num=new long[n];
    int k=0;
    while(m!=0)
    {
      num[k]=b%10;
      k++;
      b=b/10;
      m--;
    }
    long arr[]=new long[n*4];
    for(int i=0;i<n*4;i++)
    {
      arr[i]=0;
    }
    int j=0;
    for(int i=0;i<n;i++)
    {
      long a=num[i];

      {
        if(a==2 || a==3 || a==5 || a==7)
        {
          arr[j]=a;
          j++;

        }
        else if(a==4)
        {
          arr[j]=2;
          j++;
          arr[j]=2;
          j++;
          arr[j]=3;
          j++;
        }
        else if(a==6)
        {

          arr[j]=3;
          j++;
          arr[j]=5;
          j++;
        }
        else if(a==9)
        {
          arr[j]=3;
          j++;
          arr[j]=3;
          j++;
          arr[j]=2;
          j++;

          arr[j]=7;
          j++;
        }
        else if(a==8)
        {
          arr[j]=2;
          j++;
          arr[j]=2;
          j++;
          arr[j]=2;
          j++;
          arr[j]=7;
          j++;
        }

      }
    }
    Arrays.sort(arr);
    int i=n*4-1;
    while(i>-1 && arr[i]>1)
    {
      System.out.print(arr[i]);
      i--;
    }
  }
}
