#include <bits/stdc++.h>
using namespace std;
vector<int> transformdigit(int x) {
  vector<int> res;
  switch (x) {
    case 2:
      res.push_back(2);
      break;
    case 3:
      res.push_back(3);
      break;
    case 4:
      res.push_back(3);
      res.push_back(2);
      res.push_back(2);
      break;
    case 5:
      res.push_back(5);
      break;
    case 6:
      res.push_back(5);
      res.push_back(3);
      break;
    case 7:
      res.push_back(7);
      break;
    case 8:
      res.push_back(7);
      res.push_back(2);
      res.push_back(2);
      res.push_back(2);
      break;
    case 9:
      res.push_back(7);
      res.push_back(3);
      res.push_back(3);
      res.push_back(2);
      break;
  }
  return res;
}
int main() {
  int n;
  cin >> n;
  vector<int> inputs;
  int temp;
  string s;
  cin >> s;
  for (int i = 0; i < n; i++) {
    if (s[i] > 1) inputs.push_back((int)(s[i] - '0'));
  }
  vector<int> res;
  vector<int> temp1;
  for (int i = 0; i < inputs.size(); i++) {
    temp1 = transformdigit(inputs[i]);
    res.insert(res.end(), temp1.begin(), temp1.end());
  }
  sort(res.begin(), res.end());
  reverse(res.begin(), res.end());
  for (int i = 0; i < res.size(); i++) cout << res[i];
  cout << endl;
}

### 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;
vector<int> transformdigit(int x) {
  vector<int> res;
  switch (x) {
    case 2:
      res.push_back(2);
      break;
    case 3:
      res.push_back(3);
      break;
    case 4:
      res.push_back(3);
      res.push_back(2);
      res.push_back(2);
      break;
    case 5:
      res.push_back(5);
      break;
    case 6:
      res.push_back(5);
      res.push_back(3);
      break;
    case 7:
      res.push_back(7);
      break;
    case 8:
      res.push_back(7);
      res.push_back(2);
      res.push_back(2);
      res.push_back(2);
      break;
    case 9:
      res.push_back(7);
      res.push_back(3);
      res.push_back(3);
      res.push_back(2);
      break;
  }
  return res;
}
int main() {
  int n;
  cin >> n;
  vector<int> inputs;
  int temp;
  string s;
  cin >> s;
  for (int i = 0; i < n; i++) {
    if (s[i] > 1) inputs.push_back((int)(s[i] - '0'));
  }
  vector<int> res;
  vector<int> temp1;
  for (int i = 0; i < inputs.size(); i++) {
    temp1 = transformdigit(inputs[i]);
    res.insert(res.end(), temp1.begin(), temp1.end());
  }
  sort(res.begin(), res.end());
  reverse(res.begin(), res.end());
  for (int i = 0; i < res.size(); i++) cout << res[i];
  cout << endl;
}

```