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 A292 {
	public static void main(String[] args) throws IOException {
		BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
		int N = Integer.parseInt(f.readLine());
		String s = f.readLine();
		int[] g = new int[N];
		for(int i=0;i<N;i++){
			g[i] = Integer.parseInt(s.substring(i, i+1));
		}
		int[] primes = new int[10];
		for(int i=0;i<N;i++){
			int n = g[i];
			if(n==2){
				primes[2]++;
			}
			else if(n==3){
				primes[2]++; primes[3]++;
			}
			else if(n==4){
				primes[2]+=3; primes[3]++;
			}
			else if(n==5){
				primes[2]+=3; primes[3]++; primes[5]++;
			}
			else if(n==6){
				primes[2]+=4; primes[3]+=2; primes[5]++;
			}
			else if(n==7){
				primes[2]+=4; primes[3]+=2; primes[5]++; primes[7]++;
			}
			else if(n== 8){
				primes[2]+=7; primes[3]+=2; primes[5]++; primes[7]++;
			}
			else if(n==9){
				primes[2]+=7; primes[3]+=4; primes[5]++; primes[7]++;
			}
		}
		for(int i=0;i<primes[7];i++){
			System.out.print("7");
			primes[2]-=4; primes[3]-=2; primes[5]--;
		}
		for(int i=0;i<primes[5];i++){
			System.out.print("5");
			primes[2]-=3; primes[3]--;
		}
		for(int i=0;i<primes[3];i++){
			System.out.print("3");
			primes[2]--;
		}
		for(int i=0;i<primes[2];i++){
			System.out.print("2");
		}
	}
}
