#include <bits/stdc++.h>
using namespace std;
int main() {
  char ans[1000];
  char arr[20];
  int n, i, len, j;
  cin >> n;
  cin >> arr;
  j = 0;
  for (i = 0; i < n; i++) {
    if (arr[i] == '0' || arr[i] == '1')
      continue;
    else if (arr[i] == '4') {
      ans[j++] = ('3');
      ans[j++] = ('2');
      ans[j++] = ('2');
    } else if (arr[i] == '6') {
      ans[j++] = ('5');
      ans[j++] = ('3');
    } else if (arr[i] == '8') {
      ans[j++] = ('7');
      ans[j++] = ('2');
      ans[j++] = ('2');
      ans[j++] = ('2');
    } else if (arr[i] == '9') {
      ans[j++] = ('7');
      ans[j++] = ('2');
      ans[j++] = ('3');
      ans[j++] = ('3');
    } else
      ans[j++] = (arr[i]);
  }
  sort(ans, ans + j);
  for (i = j - 1; i >= 0; i--) {
    cout << ans[i];
  }
  cout << endl;
  return 0;
}

### Prompt

Construct a cpp code solution to the problem outlined:

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() {
  char ans[1000];
  char arr[20];
  int n, i, len, j;
  cin >> n;
  cin >> arr;
  j = 0;
  for (i = 0; i < n; i++) {
    if (arr[i] == '0' || arr[i] == '1')
      continue;
    else if (arr[i] == '4') {
      ans[j++] = ('3');
      ans[j++] = ('2');
      ans[j++] = ('2');
    } else if (arr[i] == '6') {
      ans[j++] = ('5');
      ans[j++] = ('3');
    } else if (arr[i] == '8') {
      ans[j++] = ('7');
      ans[j++] = ('2');
      ans[j++] = ('2');
      ans[j++] = ('2');
    } else if (arr[i] == '9') {
      ans[j++] = ('7');
      ans[j++] = ('2');
      ans[j++] = ('3');
      ans[j++] = ('3');
    } else
      ans[j++] = (arr[i]);
  }
  sort(ans, ans + j);
  for (i = j - 1; i >= 0; i--) {
    cout << ans[i];
  }
  cout << endl;
  return 0;
}

```