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.math.BigInteger;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class C515 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        char[] e = sc.next().toCharArray();
        int[] count = new int[10];
        int[] fac = new int[10];
        fac[0] = 1;
        for (int i = 1; i < 10; i++) {
            fac[i] = fac[i - 1] * i;
        }
        BigInteger result = new BigInteger("1");
        ArrayList<Integer> value = new ArrayList<Integer>();
        for (int i = 0; i < e.length; i++) {
            int temp = (int) e[i] - 48;
            check(e[i], value, count);
            BigInteger d = BigInteger.valueOf(fac[temp]);
            result = result.multiply(d);
        }
        Collections.sort(value);
        int[] a = { count[7], count[5], count[3], count[2] };
        for (int i = 0; i < 4; i++) {
            if (i == 0) {
                for (int j = 0; j < a[0]
                        && result.compareTo(BigInteger.valueOf(1)) == 1; j++) {
                    System.out.print('7');

                }
                a[1] -= a[0];
                a[2] -= 2 * a[0];
                a[3] -= 4 * a[0];
            } else if (i == 1) {
                for (int j = 0; j < a[1]
                        && result.compareTo(BigInteger.valueOf(1)) == 1; j++) {
                    System.out.print('5');
                }
                a[2] -= a[1];
                a[3] -= 3 * a[1];
            } else if (i == 2) {
                for (int j = 0; j < a[2]
                        && result.compareTo(BigInteger.valueOf(1)) == 1; j++) {
                    System.out.print('3');
                }
                a[3] -= a[2];
            } else {
                for (int j = 0; j < a[3]
                        && result.compareTo(BigInteger.valueOf(1)) == 1; j++) {
                    System.out.print('2');
                }
            }
        }

    }

    private static void check(char c, ArrayList<Integer> value, int[] count) {
        int temp = (int) c - 48;
        if (c == '1' || c == '2' || c == '3') {
            for (int i = 1; i <= temp; i++) {
                value.add(i);
                count[i]++;
            }
        } else if (c == '5') {
            value.add(5);
            count[5]++;
            c = '4';
            check(c, value, count);
        } else if (c == '7') {
            value.add(7);
            count[7]++;
            c = '6';
            check(c, value, count);
        } else if (c == '6') {
            value.add(3);
            count[3]++;
            value.add(2);
            count[2]++;
            c = '5';
            check(c, value, count);
        } else if (c == '4') {
            value.add(2);
            value.add(2);
            count[2] += 2;
            c = '3';
            check(c, value, count);
        } else if (c == '8') {
            value.add(2);
            value.add(2);
            value.add(2);
            count[2] += 3;
            c = '7';
            check(c, value, count);
        } else if (c == '9') {
            value.add(3);
            value.add(3);
            count[3] += 2;
            c = '8';
            check(c, value, count);
        } else {
            value.add(1);
        }
    }

}
