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.List;
	import java.util.Scanner;
	
	/**
	 * http://codeforces.com/contest/516/problem/C
	 *
	 */
	public class C {
		int[] res = new int[10];
	
		public static void main(String[] args) {
			new C().doJob();
		}
	
		private void doJob() {
			try (Scanner scanner = new Scanner(System.in)) {
				int n = scanner.nextInt();
				char[] a = scanner.next().toCharArray();
				List<Integer> res = new ArrayList<>(2 * n);
				for (char ai : a) {
					int number = Character.getNumericValue(ai);
					switch (number) {
					case 4:
						res.add(3);
						res.add(2);
						res.add(2);
						break;
					case 6:
						res.add(5);
						res.add(3);
						break;
					case 8:
						res.add(7);
						res.add(2);
						res.add(2);
						res.add(2);
						break;
					case 9:
						res.add(7);
						res.add(3);
						res.add(3);
						res.add(2);
						break;
					default:
						if (number > 1) {
							res.add(number);
						}
					}
				}
				Collections.sort(res, Collections.reverseOrder());
				StringBuilder builder = new StringBuilder();
				for (int digit : res) {
					builder.append(digit);
				}
				System.out.println(builder);
			}
		}
	
	}
