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.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class TC {
	static int[] ret=new int[10];
	public static void main(String[] args) {
		FastScanner in=new FastScanner();
		int i,j,n,m;
		n=in.nextInt();
		char[] d=in.nextToken().toCharArray();
		
		ArrayList<int[]> a=new ArrayList<int[]>();
		a.add(0,new int[0]);
		a.add(1,new int[0]);
		a.add(2,new int[]{2});
		a.add(3,new int[]{3});
		a.add(4,new int[]{2,2,3});
		a.add(5,new int[]{5});
		a.add(6,new int[]{3,5});
		a.add(7,new int[]{7});
		a.add(8,new int[]{2,2,2,7});
		a.add(9,new int[]{2,3,3,7});

		ArrayList<Integer> ret=new ArrayList<Integer>();
		for(i=0;i<n;i++){
			int[] b=a.get(d[i]-'0');
			m=b.length;
			for(j=0;j<m;j++){
				ret.add(b[j]);
			}
		}
		
		Collections.sort(ret);
		
		m=ret.size();
		StringBuffer ans=new StringBuffer("");
		for(i=m-1;i>=0;i--)
			ans.append(ret.get(i));
		System.out.println(ans);
	}
	static class FastScanner{
		BufferedReader br;
		StringTokenizer st;
		public FastScanner(){br=new BufferedReader(new InputStreamReader(System.in));}
		String nextToken(){
			while(st==null||!st.hasMoreElements())
				try{st=new StringTokenizer(br.readLine());}catch(Exception e){}
			return st.nextToken();
		}
		int nextInt(){return Integer.parseInt(nextToken());}
		long nextLong(){return Long.parseLong(nextToken());}
		double nextDouble(){return Double.parseDouble(nextToken());}
	}

}
