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.*;
import java.math.BigInteger;
import java.util.*;


public class A {

    void solve() throws IOException {
        int n=nextInt();
        int[] count=new int[10];
        long a=nextLong();
        while(a!=0){
            long y=a%10;
            for(int j=0;j<y;j++) {
                long x=y-j;
                for (int i = 2; i < 10; i++)
                    while (x % i == 0) {
                        count[i]++;
                        x /= i;
                    }
            }
            a/=10;
        }
        String res="";
        for(int i=9;i>=2;i--){
            while(count[i]>0){
                res+=i;
                for(int j=2;j<=i;j++){
                    int tmp=j;
                    for(int k=2;k<10;k++){
                        while(tmp%k==0){
                            count[k]--;
                            tmp/=k;
                        }
                    }
                }
                //count[i]--;
            }
        }
        out.println(res);
    }

    public static void main(String[] args) throws IOException {
        new A().run();
    }

    void run() throws IOException {
        reader = new BufferedReader(new InputStreamReader(System.in));
//      reader = new BufferedReader(new FileReader("input.txt"));
        tokenizer = null;
        out = new PrintWriter(new OutputStreamWriter(System.out));
//      out = new PrintWriter(new FileWriter("output.txt"));
        solve();
        reader.close();
        out.flush();

    }

    BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter out;

    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();
    }
}
