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.io.*;
import java.util.*;

public class A{
	public static boolean DEBUG = true;
	
	public static void main(String[] args) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(System.out);
		
		int n = nextInt(br);
		
		int twos = 0;
		int threes = 0;
		int fives = 0;
		int sevens = 0;
		
		for(int i = 0; i < n; i++){
			int next = Integer.parseInt("" + (char)(br.read()));
			
			switch(next){
				case 9:
					threes += 2;
				case 8:
					twos += 3;
				case 7:
					sevens++;
				case 6:
					twos++;
					threes++;
				case 5:
					fives++;
				case 4:
					twos += 2;
				case 3:
					threes++;
				case 2:
					twos++;
			}
		}
		
		while(sevens > 0){
			pw.print(7);
			sevens--;
			fives--;
			threes -= 2;
			twos -= 4;
		}
		
		while(fives > 0){
			pw.print(5);
			fives--;
			threes--;
			twos -= 3;
		}
		
		while(threes > 0){
			pw.print(3);
			threes--;
			twos--;
		}
		
		while(twos > 0){
			pw.print(2);
			twos--;
		}
		
		pw.println();
		
		br.close();
		pw.close();
	}
	
	public static void debug(Object o){
		if(DEBUG){
			System.out.println("~" + o);
		}
	}
	
	public static StringTokenizer getst(BufferedReader br) throws Exception{
		return new StringTokenizer(br.readLine(), " ");
	}
	
	public static int nextInt(BufferedReader br) throws Exception{
		return Integer.parseInt(br.readLine());
	}
	
	public static int nextInt(StringTokenizer st) throws Exception{
		return Integer.parseInt(st.nextToken());
	}
}