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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
	public static void main (String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader (inputStream);
		PrintWriter out = new PrintWriter (outputStream);
		TaskC solver = new TaskC ();
		solver.solve (1, in, out);
		out.close ();
	}
	
	static class TaskC {
		public void solve (int testNumber, InputReader in, PrintWriter out) {
//4!=322, 6!=53, 8!=7222, 9!=7332
			int n = in.nextInt ();
			char[] str = in.next ().toCharArray ();
			String res = "";
			int len = str.length;
			for (int i = 0; i<len; i++) {
				if (str[i] == '4') {
					res = res+"322";
				}
				else if (str[i] == '6') {
					res = res+"53";
				}
				else if (str[i] == '8') {
					res = res+"7222";
				}
				else if (str[i] == '9') {
					res = res+"7332";
				}
				else if (str[i] != '1' && str[i] != '0') {
					res = res+str[i];
				}
			}
			char[] ores = res.toCharArray ();
			len = ores.length;
			Arrays.sort (ores, 0, len);
			for (int i = len-1; i>=0; i--) {
				out.print (ores[i]);
			}
			out.println ();
		}
		
	}
	
	static class InputReader {
		private BufferedReader reader;
		private StringTokenizer tokenizer;
		
		public InputReader (InputStream stream) {
			reader = new BufferedReader (new InputStreamReader (stream), 32768);
			tokenizer = null;
		}
		
		public String next () {
			while (tokenizer == null || !tokenizer.hasMoreTokens ()) {
				try {
					String str;
					if ((str = reader.readLine ()) != null) tokenizer = new StringTokenizer (str);
					else return null;//to detect eof
				} catch (IOException e) {
					throw new RuntimeException (e);
				}
			}
			return tokenizer.nextToken ();
		}
		
		public int nextInt () {
			return Integer.parseInt (next ());
		}
		
	}
}

