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.IOException;
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) throws IOException{
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        CCF292 solver = new CCF292();
        solver.solve(1, in, out);
        out.close();
    }

    static class CCF292 {
        public void solve(int testNumber, InputReader in, PrintWriter out) throws IOException {

            int n = in.nextInt();
            String nume = in.nextLine();
            int[] hash = new int[10];
            int max = -1;
            String num = "";
            for (int i = 0; i < nume.length(); i++) {
                int act = nume.charAt(i) - '0';
                if (act > max)
                    max = act;

                for (int j = act; j > 1; j--) {
                    switch (j) {
                        case 4:
                            hash[2] += 2;
                            break;
                        case 6:
                            hash[3]++;
                            hash[2]++;
                            break;
                        case 8:
                            hash[2] += 3;
                            break;
                        case 9:
                            hash[3] += 2;
                            break;
                        default:
                            hash[j]++;
                    }
                }
            }

            for (int i = max; i > 1; i--) {
                while (hash[i] > 0) {
                    num += "" + i;
                    for (int j = i; j > 0; j--) {
                        switch (j) {
                            case 4:
                                hash[2] -= 2;
                                break;
                            case 6:
                                hash[3]--;
                                hash[2]--;
                                break;
                            case 8:
                                hash[2] -= 3;
                                break;
                            case 9:
                                hash[3] -= 2;
                                break;
                            default:
                                hash[j]--;
                        }
                    }
                }
            }
            out.println(num);
        }

    }

    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 String nextLine() throws IOException {
            return reader.readLine();
        }

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

    }
}



  	 	 		  	   					 		    		 	