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.*;

public class A {
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in); 
		int n = Integer.parseInt(scan.nextLine());
		String a = scan.nextLine();
		int[] dig = new int[10];
		for (int i = 0; i < a.length(); i++){
			switch(Character.getNumericValue(a.charAt(i))){
				case 0: break;
				case 1: break;
				case 2: dig[2]++;
						break;
				case 3: dig[3]++;
						break;
				case 4: dig[3]++;
						dig[2]+=2;
						break;
				case 5: dig[5]++;
						break;
				case 6: dig[5]++;
						dig[3]++;
						break;
				case 7: dig[7]++;
						break;
				case 8: dig[7]++;
						dig[2]+=3;
						break;
				case 9: dig[7]++;
						dig[3]+=2;
						dig[2]++;
						break;
			}
		}
		for (int i = 9; i > -1; i--){
			for (int j = 0; j < dig[i]; j++){
				System.out.print(i);
			}
		}
		System.out.println();
	}
}
