#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  long long int num;
  cin >> num;
  vector<int> list;
  while (num > 0) {
    int digit = num % 10;
    if (digit != 0 && digit != 1) {
      if (digit == 4) {
        list.push_back(3);
        list.push_back(2);
        list.push_back(2);
      } else if (digit == 6) {
        list.push_back(3);
        list.push_back(5);
      } else if (digit == 8) {
        list.push_back(2);
        list.push_back(2);
        list.push_back(2);
        list.push_back(7);
      } else if (digit == 9) {
        list.push_back(3);
        list.push_back(3);
        list.push_back(2);
        list.push_back(7);
      } else
        list.push_back(digit);
    }
    num = num / 10;
  }
  sort(list.begin(), list.end(), greater<int>());
  for (auto x : list) cout << x;
  return 0;
}

### Prompt

Please create a solution in CPP 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;
  cin >> n;
  long long int num;
  cin >> num;
  vector<int> list;
  while (num > 0) {
    int digit = num % 10;
    if (digit != 0 && digit != 1) {
      if (digit == 4) {
        list.push_back(3);
        list.push_back(2);
        list.push_back(2);
      } else if (digit == 6) {
        list.push_back(3);
        list.push_back(5);
      } else if (digit == 8) {
        list.push_back(2);
        list.push_back(2);
        list.push_back(2);
        list.push_back(7);
      } else if (digit == 9) {
        list.push_back(3);
        list.push_back(3);
        list.push_back(2);
        list.push_back(7);
      } else
        list.push_back(digit);
    }
    num = num / 10;
  }
  sort(list.begin(), list.end(), greater<int>());
  for (auto x : list) cout << x;
  return 0;
}

```