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.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;


public class A {	
	BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter out;
    
	public void solve() throws IOException {				
		int N = nextInt();
        String S = reader.readLine();
        int[] cnt = new int[10];
        for (int i = 0; i < N; i++) {
            int n = Character.getNumericValue(S.charAt(i));
            if (n == 2) {
                cnt[2]++;
            } else if (n == 3) {
                cnt[3]++;
            } else if (n == 4) {
                cnt[2]+=2;
                cnt[3]++;
            } else if (n == 5) {
                cnt[5]++;
            } else if (n == 6) {
                cnt[3]++;
                cnt[5]++;
            } else if (n == 7) {
                cnt[7]++;
            } else if (n == 8) {
                cnt[2]+=3;
                cnt[7]++;
            } else if (n == 9) {
                cnt[3]+=2;
                cnt[2]++;
                cnt[7]++;
            }
        }

        for (int i = 9; i >= 2; i--) {
            for (int j = 0; j < cnt[i]; j++) {
                out.print(i);
            }
        }
        out.println();
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		new A().run();
	}
	
	public void run() {
        try {
            reader = new BufferedReader(new InputStreamReader(System.in));
            tokenizer = null;
            out = new PrintWriter(System.out);
            solve();
            reader.close();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(1);
        }
    }

    int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }

}
