#include <bits/stdc++.h>
using namespace std;
int n, t;
char c;
vector<int> res;
void addD(int num) {
  if (num == 2 || num == 3 || num == 5 || num == 7)
    res.push_back(num);
  else {
    if (num == 4) {
      res.push_back(3);
      res.push_back(2);
      res.push_back(2);
    } else if (num == 6) {
      res.push_back(5);
      res.push_back(3);
    } else if (num == 8) {
      res.push_back(7);
      res.push_back(2);
      res.push_back(2);
      res.push_back(2);
    } else {
      res.push_back(7);
      res.push_back(3);
      res.push_back(3);
      res.push_back(2);
    }
  }
}
int main() {
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> c;
    t = c - '0';
    if (t <= 1) continue;
    addD(t);
  }
  sort(res.rbegin(), res.rend());
  for (int i = 0; i < res.size(); ++i) {
    cout << res[i];
  }
}

### Prompt

In cpp, your task is to solve 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 n, t;
char c;
vector<int> res;
void addD(int num) {
  if (num == 2 || num == 3 || num == 5 || num == 7)
    res.push_back(num);
  else {
    if (num == 4) {
      res.push_back(3);
      res.push_back(2);
      res.push_back(2);
    } else if (num == 6) {
      res.push_back(5);
      res.push_back(3);
    } else if (num == 8) {
      res.push_back(7);
      res.push_back(2);
      res.push_back(2);
      res.push_back(2);
    } else {
      res.push_back(7);
      res.push_back(3);
      res.push_back(3);
      res.push_back(2);
    }
  }
}
int main() {
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> c;
    t = c - '0';
    if (t <= 1) continue;
    addD(t);
  }
  sort(res.rbegin(), res.rend());
  for (int i = 0; i < res.size(); ++i) {
    cout << res[i];
  }
}

```