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>
// http://codeforces.com/contest/516/problem/A

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.HashMap;

public class DrazilAndFactorial {

	void start() throws IOException {	
		 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		
		 // create a hashmap with each possible digit as the key
		 HashMap<Integer,String> arr = new HashMap<Integer,String>();
		 
		 // In the following table, for each digit, start with the largest prime that
		 // is <= digit. After dividing out that factorial, do a prime factorization
		 // of the remaining digits. For example, 9 = 9 * 8 * 7!, which factors out as
		 // 3 * 3 * 2 * 2 * 2 * 7!. After regrouping the values are 7! * 3! * 3! * 2!, or "7332".
		 
		 arr.put(0,"");
		 arr.put(1,"");
		 arr.put(2,"2");
		 arr.put(3,"3");
		 arr.put(4,"322");
		 arr.put(5,"5");
		 arr.put(6,"53");
		 arr.put(7,"7");
		 arr.put(8,"7222");
		 arr.put(9,"7332");
		 
		 int numDigits = Integer.parseInt(br.readLine()); 
		 
		 String str = br.readLine();			// str = string of digits
		 
		 // for each digit, look it up in a map and return the factorization as a string 
		 StringBuilder sb = new StringBuilder("");  	    
		 for(int j=0;j < numDigits;j++){	   	 
			 sb.append(arr.get(Character.getNumericValue(str.charAt(j))));
		 }
			    
	   // store the string in a character array and sort the digits in ascending order
	    
    	char[] ch = sb.toString().toCharArray();     	     
    	Arrays.sort(ch );

    	// The String.valueOf(char[]) method converts an array of char into a string
    	// The StringBuilder.reverse method reverses a string
    	sb = new StringBuilder( String.valueOf(ch));  	   	
    	System.out.println( sb.reverse().toString() );
    	
    	// Another way to do this would be to convert the array to a List by 
    	// calling the Arrays.asList(ch) method, and then call Collections.reverse on the list.
			
	} // start
	
	public static void main(String[] args) throws IOException {		
		new DrazilAndFactorial().start();
	} 
} // class


