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.ArrayList;
import java.util.Scanner;


public class fact {
	public static void main(String args[]){
		Scanner sc=new Scanner(System.in);
		int a=sc.nextInt();
		long b=Math.abs(sc.nextLong());
		int seven=0,five=0,three=0,two=0;
		int ext3=0,ext2=0;
		for(int i=0;i<a;i++){
			if(b%10>1){
				int no=(int) (b%10);
				if(no==9){
					seven++;
					ext3+=2;
					ext2+=3;
				}else if(no==8){
					seven++;
					ext2+=3;
				}else if(no==7){
					seven++;
				}
				else if(no==6){
					five++;
					ext3++;
					ext2++;
				}
				else if(no==5){
					five++;
				}
				else if(no==4){
					three++;
					ext2+=2;
				}else if(no==3){
					three++;
				}
				else{
					two++;
				}
			}
			b=b/10;
		}
		String out="";
		for(int i=0;i<seven;i++){
			out+=7;
		}
		for(int i=0;i<five;i++){
			out+=5;
		}
		for(int i=0;i<three+ext3;i++){
			out+=3;
		}
		for(int i=0;i<two+ext2-ext3;i++){
			out+=2;
		}
		System.out.println(out);
		}
	
}
