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.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.StringTokenizer;

public class C515 {

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

    }

    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();
    }

    public static long factorial(long n) {
        return n <= 1 ? 1 : n * factorial(n - 1);
    }

    static class TaskC {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt();
            String s = in.next();
            int x;
            List<Integer> list = new ArrayList<Integer>();
            for (int i = 0; i < n; i++) {
                x = s.charAt(i) - 48;
                switch (x) {
                case 2:
                    list.add(2);
                    break;
                case 3:
                    list.add(3);
                    break;
                case 4:
                    list.add(2);
                    list.add(2);
                    list.add(3);
                    break;
                case 5:
                    list.add(5);
                    break;
                case 6:
                    list.add(5);
                    list.add(3);
                    break;
                case 7:
                    list.add(7);
                    break;
                case 8:
                    list.add(7);
                    list.add(2);
                    list.add(2);
                    list.add(2);
                    break;
                case 9:
                    list.add(2);
                    list.add(3);
                    list.add(3);
                    list.add(7);
                    break;

                default:
                    break;
                }
            }
            Collections.sort(list, Collections.reverseOrder());
            for (int i = 0; i < list.size(); i++) {
                System.out.print(list.get(i));
            }
        }
    }
}
