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 Main {

	BufferedReader in;
	StringTokenizer str = null;
	PrintWriter out;
	
	private String next() throws Exception{
		while (str == null || !str.hasMoreElements())
			str = new StringTokenizer(in.readLine());
		return str.nextToken();
	}
	
	private int nextInt() throws Exception{
		return Integer.parseInt(next());
	}
	
	private long nextLong() throws Exception{
		return Long.parseLong(next());
	}
	
	private double nextDouble() throws Exception{
		return Double.parseDouble(next());
	}
	
	public void run() throws Exception{
		in =  new BufferedReader(new InputStreamReader(System.in));
		out = new PrintWriter(System.out);
		int n = nextInt();
		char []a = next().toCharArray();
		int []c = new int[10];
		for(int i = 0; i < n; ++i) c[a[i] - '0']++;
		int []ret = new int[10];
		for(int i = 0; i < 10; ++i) {
			if (c[i] == 0) continue;
			if (i == 2 || i == 3 || i == 5 || i == 7) {
				ret[i] += c[i];
			}else {
				if (i == 4) {
					ret[2] += 2 * c[i];
					ret[3] += c[i];
				}else if (i == 6) {
					ret[5] += c[i];
					ret[3] += c[i];
				}else if (i == 8) {
					ret[2] += 3 * c[i];
					ret[7] += c[i];
				}else if (i == 9) {
					ret[7] += c[i];;
					ret[3] += 2 * c[i];
					ret[2] += c[i];
				}
			}
		}

		for(int i = 9; i > 1; --i) {
			for(int j = 0; j < ret[i]; ++j) {
				out.print(i);
			}
		}
		out.println();
		out.close();
	}
		
	public static void main(String[] args) throws Exception{
		new Main().run();
	}
}
