#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  char s[16];
  string two = "2";
  string three = "3";
  string four = "322";
  string five = "5";
  string six = "53";
  string seven = "7";
  string eight = "7222";
  string nine = "7332";
  cin >> n;
  cin >> s;
  string ans;
  int r;
  for (int i = 0; i < strlen(s); i++) {
    r = s[i] - 48;
    switch (r) {
      case 2:
        ans = ans + two;
        break;
      case 3:
        ans = ans + three;
        break;
      case 4:
        ans = ans + four;
        break;
      case 5:
        ans = ans + five;
        break;
      case 6:
        ans = ans + six;
        break;
      case 7:
        ans = ans + seven;
        break;
      case 8:
        ans = ans + eight;
        break;
      case 9:
        ans = ans + nine;
        break;
      default:
        break;
    }
  }
  sort(ans.begin(), ans.end());
  reverse(ans.begin(), ans.end());
  cout << ans;
}

### 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() {
  int n;
  char s[16];
  string two = "2";
  string three = "3";
  string four = "322";
  string five = "5";
  string six = "53";
  string seven = "7";
  string eight = "7222";
  string nine = "7332";
  cin >> n;
  cin >> s;
  string ans;
  int r;
  for (int i = 0; i < strlen(s); i++) {
    r = s[i] - 48;
    switch (r) {
      case 2:
        ans = ans + two;
        break;
      case 3:
        ans = ans + three;
        break;
      case 4:
        ans = ans + four;
        break;
      case 5:
        ans = ans + five;
        break;
      case 6:
        ans = ans + six;
        break;
      case 7:
        ans = ans + seven;
        break;
      case 8:
        ans = ans + eight;
        break;
      case 9:
        ans = ans + nine;
        break;
      default:
        break;
    }
  }
  sort(ans.begin(), ans.end());
  reverse(ans.begin(), ans.end());
  cout << ans;
}

```