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.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/**
 * Created by slycer on 4/7/16.
 */
public class DrazilandFactorial {


    public static void main ( String [] args ) throws IOException {
        FastReader reader = new FastReader();
        reader.nextLineAsInt();
        int n = reader.nextInt();
        String line = reader.nextLine();
        List<Integer> answer = new ArrayList<>();

        for ( int i=0; i<line.length(); i++ ){
            char c = line.charAt( i );
            int value = Integer.valueOf( c + "" );
            if ( value == 2 ){
                answer.add( 2 );
            }
            if ( value == 3 ){
                answer.add( 3 );
            }
            if ( value == 4 ){
                answer.add( 3 );
                answer.add( 2 );
                answer.add( 2 );
            }
            if ( value == 5 ){
                answer.add( 5 );
            }
            if ( value == 6 ){
                answer.add( 5 );
                answer.add( 3 );
            }
            if ( value == 7 ){
                answer.add( 7 );
            }
            if ( value == 8 ){
                answer.add( 7 );
                answer.add( 2 );
                answer.add( 2 );
                answer.add( 2 );
            }
            if ( value == 9 ){
                answer.add( 3 );
                answer.add( 3 );
                answer.add( 7 );
                answer.add( 2 ); 
            }
        }
        Collections.sort( answer );
        Collections.reverse( answer );
        for ( int i : answer ){
            System.out.print( i );
        }
    }

    public static class FastReader {
        private BufferedReader reader;
        private int [] lastLineAsInt;
        private int pos;

        public FastReader (){
            reader = new BufferedReader( new InputStreamReader( System.in ) );
        }
        public long [] nextLineAsLong() throws IOException {
            String [] aux = reader.readLine().split( " " );
            long [] ret = new long[ aux.length ];
            for ( int i=0; i<aux.length; i++ ){
                ret[i] = Integer.valueOf( aux[i] );
            }
            return ret;
        }

        public int [] nextLineAsInt() throws IOException {
            String [] aux = reader.readLine().split( " " );
            int [] ret = new int[ aux.length ];
            for ( int i=0; i<aux.length; i++ ){
                ret[i] = Integer.valueOf( aux[i] );
            }
            pos = 0;
            lastLineAsInt = ret;
            return ret;
        }

        public int nextInt(){
            return lastLineAsInt[pos++];
        }

        public String nextLine() throws IOException {
            return reader.readLine();
        }
    }

}
