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.Scanner;

public class wow {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner scan = new Scanner(System.in);
		int[] checkNum = new int[10];
		int getNumLen = scan.nextInt();
		long num = scan.nextLong();
		
		
		for(int i = 0; i < getNumLen; i++)
		{
			int temp = (int)(num%10); num /=10;
			switch(temp)
			{
			case 9:
				checkNum[3]+=2;
			case 8:
				checkNum[2]+=3;
			case 7:
				checkNum[7]++;
			case 6:
				checkNum[3]++;checkNum[2]++;
			case 5:
				checkNum[5]++;
			case 4:
				checkNum[2]+=2;
			case 3:
				checkNum[3]++;
			case 2:
				checkNum[2]++;
				break;
			}
		}
		
		while(true)
		{
			if(checkNum[7] != 0)
			{
				checkNum[7]--;
				checkNum[3]-=2;
				checkNum[5]--;
				checkNum[2]-=4;
				System.out.print("7");
			}
			else if(checkNum[5] != 0)
			{
				checkNum[5]--;
				checkNum[3]--;
				checkNum[2]-=3;
				System.out.print("5");
			}
			else if(checkNum[3] != 0)
			{
				checkNum[3]--;
				checkNum[2]--;
				System.out.print("3");
			}
			else if(checkNum[2] != 0)
			{
				checkNum[2]--;
				System.out.print("2");
			}
			else
				break;
		}
	}
	
	
}
