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.*;
import java.io.*;


public class C implements Runnable {
		
	public void solve() throws IOException {
                int N = nextInt();
                String s = nextToken();
                ArrayList<Integer> al = new ArrayList<Integer>();
                for(char c : s.toCharArray()){
                        switch(c){
                                case '2' :
                                        al.add(2);
                                        break;
                                case '3' :
                                        al.add(3);
                                        break;
                                case '4' :
                                        al.add(3) ; al.add(2); al.add(2);
                                        break;
                                case '5' :
                                        al.add(5);
                                        break;
                                case '6' :
                                        al.add(5); al.add(3);
                                        break;
                                case '7' :
                                        al.add(7);
                                        break;
                                case '8' :
                                        al.add(7); al.add(2); al.add(2); al.add(2);
                                        break;
                                case '9' :
                                        al.add(7); al.add(3); al.add(3); al.add(2);
                                        break;
                        }
                }
                
                Collections.sort(al);
                for(int i = al.size() - 1; i >= 0; i--){
                        out.print(al.get(i));
                }
                out.println();
	}

	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	//-----------------------------------------------------------
	public static void main(String[] args) {
		new C().run();
	}

        public void debug(Object... arr){
            System.out.println(Arrays.deepToString(arr));
        }

        public void print1Int(int[] a){
                for(int i = 0; i < a.length; i++)
                        System.out.print(a[i] + " ");
                System.out.println();
        }
        
        public void print2Int(int[][] a){
                for(int i = 0; i < a.length; i++){
                        for(int j = 0; j < a[0].length; j++){
                                System.out.print(a[i][j] + " ");
                        }
                        System.out.println();
                }
        }
        
	public void run() {
		try {
			in = new BufferedReader(new InputStreamReader(System.in));
                        out = new PrintWriter(System.out);
			tok = null;
			solve();
			in.close();
                        out.close();
		} catch (IOException e) {
			System.exit(0);
		}
	}

	public String nextToken() throws IOException {
		while (tok == null || !tok.hasMoreTokens()) {
			tok = new StringTokenizer(in.readLine());
		}
		return tok.nextToken();
	}

	public int nextInt() throws IOException {
		return Integer.parseInt(nextToken());
	}

	public long nextLong() throws IOException {
		return Long.parseLong(nextToken());
	}

	public double nextDouble() throws IOException {
		return Double.parseDouble(nextToken());
	}
        PrintWriter out;
	BufferedReader in;
	StringTokenizer tok;
}