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;

public class a {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    in.readLine();
    String x = in.readLine();
    int cnt2 = 0;
    int cnt3 = 0;
    int cnt5 = 0;
    int cnt7 = 0;
    for (char digit: x.toCharArray()) {
      if (digit == '2') {
        ++cnt2;
      } else if (digit == '3') {
        ++cnt2;
        ++cnt3;
      } else if (digit == '4') {
        cnt2 += 3;
        ++cnt3;
      } else if (digit == '5') {
        cnt2 += 3;
        ++cnt3;
        ++cnt5;
      } else if (digit == '6') {
        cnt2 += 4;
        cnt3 += 2;
        ++cnt5;
      } else if (digit == '7') {
        cnt2 += 4;
        cnt3 += 2;
        ++cnt5;
        ++cnt7;
      } else if (digit == '8') {
        cnt2 += 7;
        cnt3 += 2;
        ++cnt5;
        ++cnt7;
      } else if (digit == '9') {
        cnt2 += 7;
        cnt3 += 4;
        ++cnt5;
        ++cnt7;
      }
    }
    StringBuilder output = new StringBuilder();
    while (cnt7 > 0) {
      output.append('7');
      --cnt7;
      --cnt5;
      cnt3 -= 2;
      cnt2 -= 4;
    }
    while (cnt5 > 0) {
      output.append('5');
      --cnt5;
      --cnt3;
      cnt2 -= 3;
    }
    while (cnt3 > 0) {
      output.append('3');
      --cnt3;
      --cnt2;
    }
    while (cnt2 > 0) {
      output.append('2');
      --cnt2;
    }
    System.out.println(output);
  }
}
