#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  int n;
  cin >> n;
  char a[n];
  int b[100], k = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (a[i] == '2')
      b[k++] = 2;
    else if (a[i] == '3')
      b[k++] = 3;
    else if (a[i] == '4') {
      b[k++] = 3;
      b[k++] = 2;
      b[k++] = 2;
    } else if (a[i] == '5') {
      b[k++] = 5;
    } else if (a[i] == '6') {
      b[k++] = 5;
      b[k++] = 3;
    } else if (a[i] == '7')
      b[k++] = 7;
    else if (a[i] == '8') {
      b[k++] = 7;
      b[k++] = 2;
      b[k++] = 2;
      b[k++] = 2;
    } else if (a[i] == '9') {
      b[k++] = 7;
      b[k++] = 3;
      b[k++] = 3;
      b[k++] = 2;
    }
  }
  sort(b, b + k, greater<int>());
  for (int i = 0; i < k; i++) cout << b[i];
  cout << endl;
  return 0;
}

### Prompt

Your task is to create a cpp solution to the following problem:

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() {
  ios_base::sync_with_stdio(false);
  int n;
  cin >> n;
  char a[n];
  int b[100], k = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (a[i] == '2')
      b[k++] = 2;
    else if (a[i] == '3')
      b[k++] = 3;
    else if (a[i] == '4') {
      b[k++] = 3;
      b[k++] = 2;
      b[k++] = 2;
    } else if (a[i] == '5') {
      b[k++] = 5;
    } else if (a[i] == '6') {
      b[k++] = 5;
      b[k++] = 3;
    } else if (a[i] == '7')
      b[k++] = 7;
    else if (a[i] == '8') {
      b[k++] = 7;
      b[k++] = 2;
      b[k++] = 2;
      b[k++] = 2;
    } else if (a[i] == '9') {
      b[k++] = 7;
      b[k++] = 3;
      b[k++] = 3;
      b[k++] = 2;
    }
  }
  sort(b, b + k, greater<int>());
  for (int i = 0; i < k; i++) cout << b[i];
  cout << endl;
  return 0;
}

```