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.InputStreamReader;

import static java.lang.Integer.parseInt;

/**
 * TODO: describe
 *
 * @author keks
 */
public class A {
    public static void main(String[] args) throws IOException {
        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        final int n = parseInt(reader.readLine());
        final String a = reader.readLine();
        System.out.println(get(n, a));
    }

    public static String get(int n, String s) {
        final char[] chars = s.toCharArray();
        final int[] d = new int[10];
        for (char ch : chars) {
            switch (ch - '0') {
                case 2:
                    d[2] += 1;
                    break;
                case 3:
                    d[3] += 1;
                    break;
                case 4:
                    d[2] += 2;
                    d[3] += 1;
                    break;
                case 5:
                    d[5] += 1;
                    break;
                case 6:
                    d[3] += 1;
                    d[5] += 1;
                    break;
                case 7:
                    d[7] += 1;
                    break;
                case 8:
                    d[2] += 3;
                    d[7] += 1;
                    break;
                case 9:
                    d[2] += 1;
                    d[3] += 2;
                    d[7] += 1;
                default:
            }
        }

        final StringBuilder builder = new StringBuilder();
        for (int i = 9; i > 1; i--) {
            for (; d[i] != 0; d[i]--) {
                builder.append((char) ('0' + i));
            }
        }
        return builder.toString();
    }
}
