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.lang.*;
import java.io.*;
public final class GFG {
	public static void main (String[] args) {
    	solve();
	}
	static void solve() {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	String s = sc.next();
    	int[][] factorial = {
    	    {0, 0, 0, 0},
    	    {0, 0, 0, 0},
    	    {1, 0, 0, 0},
    	    {1, 1, 0, 0},
    	    {3, 1, 0, 0},
    	    {3, 1, 1, 0},
    	    {4, 2, 1, 0},
    	    {4, 2, 1, 1},
    	    {7, 2, 1, 1},
    	    {7, 4, 1, 1}
    	};
    	int[] nums = new int[4];
    	for(char ch: s.toCharArray()) {
    	    int[] no = factorial[ch-'0'];
    	    for(int i = 0; i<4; i++)
        	    nums[i]+=no[i];
    	}
    	int nums7 = 0;
    	while(nums[3]>0) {
    	    for(int i = 0; i<4; i++)
        	    nums[i]-=factorial[7][i];
    	    nums7++;
    	}
    	int nums5 = 0;
    	while(nums[2]>0) {
    	    for(int i = 0; i<4; i++)
        	    nums[i]-=factorial[5][i];
        	nums5++;
    	}
    	int nums3 = 0;
    	while(nums[1]>0) {
    	    for(int i = 0; i<4; i++)
        	    nums[i]-=factorial[3][i];
        	nums3++;
    	}
    	int nums2 = 0;
    	while(nums[0]>0) {
    	    for(int i = 0; i<4; i++)
        	    nums[i]-=factorial[2][i];
        	nums2++;
    	}
    	StringBuilder sb = new StringBuilder();
    	int[] x = new int[]{nums7, nums5, nums3, nums2};
    	char[] p = new char[]{'7', '5', '3', '2'};
    	for(int i = 0; i<4; i++) {
    	    int u = x[i];
    	    for(int j = 0; j<u; j++)
        	    sb.append(p[i]);
    	}
    	System.out.println(sb.toString());
	}
}