#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, b, c;
  cin >> a >> b;
  vector<int> v;
  while (b) {
    c = b % 10;
    b /= 10;
    if (c == 1) continue;
    switch (c) {
      case 2: {
        v.push_back(2);
        break;
      }
      case 3: {
        v.push_back(3);
        break;
      }
      case 4: {
        v.push_back(2);
        v.push_back(2);
        v.push_back(3);
        break;
      }
      case 5: {
        v.push_back(5);
        break;
      }
      case 6: {
        v.push_back(5);
        v.push_back(3);
        break;
      }
      case 7: {
        v.push_back(7);
        break;
      }
      case 8: {
        v.push_back(7);
        v.push_back(2);
        v.push_back(2);
        v.push_back(2);
        break;
      }
      case 9: {
        v.push_back(7);
        v.push_back(2);
        v.push_back(3);
        v.push_back(3);
        break;
      }
    }
  }
  sort(v.begin(), v.end(), greater<int>());
  for (int i = 0; i < v.size(); i++) cout << v[i];
}

### Prompt

Please provide a cpp coded solution 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() {
  long long a, b, c;
  cin >> a >> b;
  vector<int> v;
  while (b) {
    c = b % 10;
    b /= 10;
    if (c == 1) continue;
    switch (c) {
      case 2: {
        v.push_back(2);
        break;
      }
      case 3: {
        v.push_back(3);
        break;
      }
      case 4: {
        v.push_back(2);
        v.push_back(2);
        v.push_back(3);
        break;
      }
      case 5: {
        v.push_back(5);
        break;
      }
      case 6: {
        v.push_back(5);
        v.push_back(3);
        break;
      }
      case 7: {
        v.push_back(7);
        break;
      }
      case 8: {
        v.push_back(7);
        v.push_back(2);
        v.push_back(2);
        v.push_back(2);
        break;
      }
      case 9: {
        v.push_back(7);
        v.push_back(2);
        v.push_back(3);
        v.push_back(3);
        break;
      }
    }
  }
  sort(v.begin(), v.end(), greater<int>());
  for (int i = 0; i < v.size(); i++) cout << v[i];
}

```