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

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Vadim Semenov
 */
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();
	}
}

class TaskA {
    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int length = in.nextInt();
        long number = in.nextLong();
        int[] cnt = new int[10];
        while (number > 0) {
            cnt[(int) (number % 10)]++;
            number /= 10;
        }
        if (cnt[9] > 0) {
            cnt[7] += 1 * cnt[9];
            cnt[3] += 2 * cnt[9];
            cnt[2] += 1 * cnt[9];
            cnt[9] = 0;
        }
        if (cnt[8] > 0) {
            cnt[2] += 3 * cnt[8];
            cnt[7] += cnt[8];
            cnt[8] = 0;
        }
        if (cnt[6] > 0) {
            cnt[3] += cnt[6];
            cnt[5] += cnt[6];
            cnt[6] = 0;
        }
        if (cnt[4] > 0) {
            cnt[3] += cnt[4];
            cnt[2] += 2 * cnt[4];
            cnt[4] = 0;
        }
        for (int i = 9; i > 1; --i) {
            for (int j = 0; j < cnt[i]; ++j) {
                out.print(i);
            }
        }
        out.println();
    }
}

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

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

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

    public long nextLong() {
        return Long.parseLong(next());
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(readLine());
        }
        return tokenizer.nextToken();
    }

    public String readLine() {
        String line;
        try {
            line = reader.readLine();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return line;
    }
}

