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.StringTokenizer;
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);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt();
            String a = in.next();
            int[] aCount = new int[10];
            for (int i = 0; i < n; i++) {
                for (int j = a.charAt(i) - '0'; j > 1; j--) {
                    aCount[j]++;
                }
            }
            aCount[3] += 2 * aCount[9];
            aCount[9] = 0;
            aCount[2] += 3 * aCount[8];
            aCount[8] = 0;
            int maxStill = aCount[7];
            aCount[2] += aCount[6] - maxStill;
            aCount[3] += aCount[6] - maxStill;
            aCount[6] = maxStill;
            maxStill = Math.max(maxStill, aCount[5]);
            aCount[2] += 2 * (aCount[4] - maxStill);
            aCount[4] = maxStill;

            int[] xFactCount = new int[10];
            for (int i = 9; i > 1; i--) {
                if (aCount[i] != 0) {
                    xFactCount[i] = aCount[i];
                    for (int j = i; j > 1; j--) {
                        aCount[j] -= xFactCount[i];
                    }
                }
            }
            for (int i = 9; i > 1; i--) {
                for (int j = 0; j < xFactCount[i]; j++) {
                    out.print(i);
                }
            }
        }

    }

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

        public InputReader(InputStream inputStream) {
            reader = new BufferedReader(new InputStreamReader(inputStream));
        }

        private void fillTokenizer() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }
            }
        }

        public String next() {
            fillTokenizer();
            return tokenizer.nextToken();
        }

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

    }
}

