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.*;
import java.io.*;

public class Factorial{
	public static void main(String[]args) throws Exception{
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		int[] nums = new int[10];
		boolean[] primes = new boolean[10];
		primes[2] = true;
		primes[3] = true;
		primes[5] = true;
		primes[7] = true;
		int n = Integer.parseInt(in.readLine());
		String g = in.readLine();
		for(int i=0; i<n; i++){
			int x = g.charAt(i)-'0';
			for(int o=2; o<=x; o++) nums[o]++;
		}
		// System.out.println(Arrays.toString(nums));
		if(nums[9]>0){
			nums[3]+=(nums[9]*2);
			nums[9] = 0;
		}
		if(nums[8]>0){
			nums[2]+=(nums[8]*3);
			nums[8] = 0;
		}
		// System.out.println(Arrays.toString(nums));
		for(int i=7; i>=2; i--){
			// System.out.println(Arrays.toString(nums));
			if(primes[i]){
				if(nums[i]==0) continue;
				for(int o=0; o<nums[i]; o++) sb.append(i);
				for(int o=2; o<=i; o++) nums[o]-=nums[i];
			}
			else{
				if(i==6){
					nums[2]+=nums[6];
					nums[3]+=nums[6];
					nums[6] = 0;
				}
				else if(i==4){
					nums[2]+=(nums[4]*2);
					nums[4] = 0;
				}
			}
		}
		// System.out.println(Arrays.toString(nums));
		System.out.println(sb);
	}
}