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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class Main {
	public static void main(String args[]) throws IOException{
		Reader.init(System.in);
		int n=Reader.nextInt();
		char c[]=Reader.readCharWord();
		int a[]=new int[n];
		ArrayList<Integer> re=new ArrayList<Integer>();
		for(int i=0;i<n;i++){
			a[i]=Integer.parseInt(""+c[i]);
		}
		for(int i=0;i<n;i++){
			int max=i;
			for(int j=i;j<n;j++){
				if(a[j]>a[max]){
					max=j;
				}
			}
			int t=a[i];
			a[i]=a[max];
			a[max]=t;
		}
		for(int i=0;i<n;i++){
			if(a[i]==9){
				re.add(3);
				re.add(3);
				re.add(2);
				re.add(7);
			}else if(a[i]==8){
				re.add(2);
				re.add(2);
				re.add(2);
				re.add(7);
			}else if(a[i]==7){
				re.add(7);
			}else if(a[i]==6){
				re.add(3);
				re.add(5);
				
			}else if(a[i]==5){
				re.add(5);
			}else if(a[i]==4)
			{
				re.add(3);
				re.add(2);
				re.add(2);
			}else if(a[i]==3){
				re.add(3);
			}else if(a[i]==2){
				re.add(2);
			}
		}
		Collections.sort(re);
		for(int i=re.size()-1;i>=0;i--){
			System.out.print(re.get(i));
		}
	}
	
	public static int gcd(int a,int b){
		int gcd=b;
		if(a>=b){
			if(a%b!=0){
				gcd=gcd(a%b,b);
			}else
				return b;
		}else{
			if(b%a!=0){
				gcd=gcd(b%a,a);
			}else
				return a;
		}
		return gcd;
	}
}


/** Class for buffered reading int and double values */
class Reader {
	static BufferedReader reader;
	static StringTokenizer tokenizer;

	/** call this method to initialize reader for InputStream */
	static void init(InputStream input) {
		reader = new BufferedReader(new InputStreamReader(input));
		tokenizer = new StringTokenizer("");
	}

	/** get next word */
	static String next() throws IOException {
		while (!tokenizer.hasMoreTokens()) {
			// TODO add check for eof if necessary
			tokenizer = new StringTokenizer(reader.readLine());
		}
		return tokenizer.nextToken();
	}

	static int nextInt() throws IOException {
		return Integer.parseInt(next());
	}
	 static char[] readCharWord() throws IOException{
	    	return next().toCharArray();
	    }
	static long nextLong() throws IOException {
		return Long.parseLong(next());
	}
}
