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.*;
import java.math.BigInteger;
import java.util.*;

public class Main {
    private static PrintWriter out;
    private static FastReader in;

    private static class FastReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public FastReader(InputStream inputStream) {
            reader = new BufferedReader(
                    new InputStreamReader(inputStream), 1 << 16);
            tokenizer = null;
        }

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

        public String nextLine() {
            try {
                return reader.readLine();
            }
            catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        }

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

    }

    public static void main(String[] args) throws FileNotFoundException {
        in = new FastReader(System.in);
        out = new PrintWriter(System.out);

        int n = in.nextInt();
        char[] A = in.next().toCharArray();
        int[] factors = new int[]{0, 0, 0, 0};
        int[][] factorials = new int[][]
                {
                        {0, 0, 0, 0},
                        {0, 0, 0, 0},
                        {1, 0, 0, 0},
                        {1, 1, 0, 0},
                        {3, 1, 0, 0},
                        {3, 1, 1, 0},
                        {4, 2, 1, 0},
                        {4, 2, 1, 1},
                        {7, 2, 1, 1},
                        {7, 4, 1, 1}
                };
        for (char c : A) {
            for (int i = 0; i < 4; ++i) {
                factors[i] += factorials[c - '0'][i];
            }
        }
        for (int i = 0; i < factors[3]; ++i) {
            out.print('7');
        }
        for (int i = 0; i < factors[2] - factors[3]; ++i) {
            out.print('5');
        }

        for (int i = 0; i < factors[1] - factors[2] - factors[3]; ++i) {
            out.print('3');
        }

        for (int i = 0; i < factors[0] - factors[1] - 2*factors[2]; ++i) {
            out.print('2');
        }
        out.println();

        out.flush();
    }
}