#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  char arr[10 * n], brr[10 * n];
  cin >> arr;
  int count = 0;
  for (int i = 0; i < n; i++) {
    if (arr[i] != '0' && arr[i] != '1') {
      if (arr[i] == '4') {
        brr[count] = '2';
        count++;
        brr[count] = '2';
        count++;
        brr[count] = '3';
        count++;
      } else if (arr[i] == '8') {
        brr[count] = '2';
        count++;
        brr[count] = '2';
        count++;
        brr[count] = '2';
        count++;
        brr[count] = '7';
        count++;
      } else if (arr[i] == '6') {
        brr[count] = '3';
        count++;
        brr[count] = '5';
        count++;
      } else if (arr[i] == '9') {
        brr[count] = '2';
        count++;
        brr[count] = '3';
        count++;
        brr[count] = '3';
        count++;
        brr[count] = '7';
        count++;
      } else {
        brr[count] = arr[i];
        count++;
      }
    }
  }
  sort(brr, brr + count);
  for (int i = count - 1; i >= 0; i--) cout << brr[i];
}

### Prompt

Develop a solution in CPP to the problem described below:

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>

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  char arr[10 * n], brr[10 * n];
  cin >> arr;
  int count = 0;
  for (int i = 0; i < n; i++) {
    if (arr[i] != '0' && arr[i] != '1') {
      if (arr[i] == '4') {
        brr[count] = '2';
        count++;
        brr[count] = '2';
        count++;
        brr[count] = '3';
        count++;
      } else if (arr[i] == '8') {
        brr[count] = '2';
        count++;
        brr[count] = '2';
        count++;
        brr[count] = '2';
        count++;
        brr[count] = '7';
        count++;
      } else if (arr[i] == '6') {
        brr[count] = '3';
        count++;
        brr[count] = '5';
        count++;
      } else if (arr[i] == '9') {
        brr[count] = '2';
        count++;
        brr[count] = '3';
        count++;
        brr[count] = '3';
        count++;
        brr[count] = '7';
        count++;
      } else {
        brr[count] = arr[i];
        count++;
      }
    }
  }
  sort(brr, brr + count);
  for (int i = count - 1; i >= 0; i--) cout << brr[i];
}

```