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.*;
import java.math.*;
public class Euler {
	
	static class FastReader {
		BufferedReader br;
		StringTokenizer st;
 
		public FastReader() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}
 
		String next() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}
 
		int nextInt() {
			return Integer.parseInt(next());
		}
 
		long nextLong() {
			return Long.parseLong(next());
		}
 
		double nextDouble() {
			return Double.parseDouble(next());
		}
 
		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}
 
	
	public static void main(String[] args){
		
		FastReader in = new FastReader();
		PrintWriter o = new PrintWriter(System.out);
		
		int n = in.nextInt();
		List<Integer> list = new ArrayList<>();
		String str = in.next();
		
		for (int i = 0; i < str.length(); i++) {
			
			int x = str.charAt(i) - '0';
			if (x != 1 && x != 0) {
				if (x == 2) list.add(x);
				if (x == 3) list.add(x);
				if (x == 4) {
					list.add(2);
					list.add(2);
					list.add(3);
				}
				if (x == 5) {
					list.add(5);
				}
				if (x == 6) {
					list.add(5);
					list.add(3);
				}
				if (x == 7)  {
					list.add(7);
				}
				if (x == 8) {
					list.add(2);
					list.add(2);
					list.add(2);
					list.add(7);
				}
				if (x == 9) {
					list.add(3);
					list.add(3);
					list.add(2);
					list.add(7);
				}
				
			}
			
			
		}
		
		Collections.sort(list);
		for (int i = list.size() - 1; i >= 0; i--) {
			
			System.out.print(list.get(i));
			
		}
		System.out.println();
		
		
		
		
		
		o.flush();
		o.close();
		
		
		
	}
}
