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.StringTokenizer;

public class CF292C {
	private FastScanner in;
	private PrintWriter out;

	public void solve() throws IOException {
		int[] fact = {1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880};
		int[] digs = new int[10];
		int n = in.nextInt();
		String s = in.next();
		long sum = 1;
		for (int i = 0; i < n; i++){
			int dig = s.charAt(i) - '0';
			if (dig == 2){ digs[2]++; }
			if (dig == 3){ digs[3]++; }
			if (dig == 4){ digs[3]++; digs[2] += 2; }
			if (dig == 5){ digs[5]++; }
			if (dig == 6){ digs[5]++; digs[3]++; }
			if (dig == 7){ digs[7]++; }
			if (dig == 8){ digs[7]++; digs[2] += 3; }
			if (dig == 9){ digs[7]++; digs[3] += 2; digs[2]++; }
		}
		String res = "";
		for (int i = 9; i >= 2; i--){
			if (digs[i] > 0){
				for (int j = 0; j < digs[i]; j++){
					res += i;
				}
			}
		}
		out.println(res);
	}

	public static void main(String[] args) {
		new CF292C().run();
	}

	public void run() {
		try {
			in = new FastScanner();
			out = new PrintWriter(System.out);
			solve();
			out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private class FastScanner {
		private BufferedReader br;
		private StringTokenizer st;

		public FastScanner() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		public String next() {
			while (st == null || !st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		public int nextInt() {
			return Integer.parseInt(next());
		}

		public long nextLong() {
			return Long.parseLong(next());
		}

		public double nextDouble() {
			return Double.parseDouble(next());
		}
	}
}
