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

public class CF292_A {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		Scanner in = new Scanner(System.in);

		int N = in.nextInt();

		char[] num = in.next().toCharArray();

		ArrayList<Integer> outNums = new ArrayList<Integer>();

		for (int i = 0; i < N; i++) {

			if (num[i] == '2') {
				outNums.add(2);
			}
			if (num[i] == '3') {
				outNums.add(3);
			}
			if (num[i] == '4') {
				outNums.add(3);
				outNums.add(2);
				outNums.add(2);
			}
			if (num[i] == '5') {
				outNums.add(5);
			}
			if (num[i] == '6') {
				outNums.add(5);
				outNums.add(3);
			}
			if (num[i] == '7') {
				outNums.add(7);
			}
			if (num[i] == '8') {
				outNums.add(7);
				outNums.add(2);
				outNums.add(2);
				outNums.add(2);
			}
			if (num[i] == '9') {
				outNums.add(7);
				outNums.add(3);
				outNums.add(3);
				outNums.add(2);
			}

		}
		
		Collections.sort(outNums);
		
		for(int i = outNums.size()-1; i >= 0; i--) {
				System.out.print(outNums.get(i));
		}
		System.out.println();

	}

}
