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.util.Scanner;

/**
 * Created by yuu on 21/3/17.
 */
public class Problem515C {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String num = sc.next();
        int[] counter = new int[10];
        for (char digit : num.toCharArray()){
            switch(digit){
                case '2':
                    counter[2]++;
                    break;
                case '3':
                    counter[3]++;
                    break;
                case '4':
                    counter[2]+=2;
                    counter[3]++;
                    break;
                case '5':
                    counter[5]++;
                    break;
                case '6':
                    counter[5]++;
                    counter[3]++;
                    break;
                case '7':
                    counter[7]++;
                    break;
                case '8':
                    counter[7]++;
                    counter[2]+=3;
                    break;
                case '9':
                    counter[7]++;
                    counter[3]+=2;
                    counter[2]++;
                    break;
                default:
                    break;
            }
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 9; i > 1; i--){
            int count = counter[i];
            for (int j = 0; j < count; j++){
                sb.append(i);
            }
        }
        System.out.println(sb);
    }
}
