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
	    	String s = new StringBuilder(String.valueOf(ch)).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.
	     
	     System.out.println(s);
			
	} // start
	
	public static void main(String[] args) throws IOException {		
		new DrazilAndFactorial().start();
	} 
} // class


