#include <bits/stdc++.h>
using namespace std;
int fact[10][6] = {{0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0}, {2, 0, 0, 0, 0, 0},
                   {3, 0, 0, 0, 0, 0}, {2, 2, 3, 0, 0, 0}, {5, 0, 0, 0, 0, 0},
                   {5, 3, 0, 0, 0, 0}, {7, 0, 0, 0, 0, 0}, {7, 2, 2, 2, 0, 0},
                   {7, 3, 3, 2, 0, 0}};
vector<int> num;
int main() {
  num.clear();
  int n;
  string s;
  cin >> n >> s;
  for (int i = 0; i < n; i++) {
    for (int j = 0; fact[s[i] - '0'][j]; j++) {
      num.push_back(fact[s[i] - '0'][j]);
    }
  }
  sort(num.rbegin(), num.rend());
  for (int i = 0; i < num.size(); i++) {
    cout << num[i];
  }
  cout << endl;
}

### 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 fact[10][6] = {{0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0}, {2, 0, 0, 0, 0, 0},
                   {3, 0, 0, 0, 0, 0}, {2, 2, 3, 0, 0, 0}, {5, 0, 0, 0, 0, 0},
                   {5, 3, 0, 0, 0, 0}, {7, 0, 0, 0, 0, 0}, {7, 2, 2, 2, 0, 0},
                   {7, 3, 3, 2, 0, 0}};
vector<int> num;
int main() {
  num.clear();
  int n;
  string s;
  cin >> n >> s;
  for (int i = 0; i < n; i++) {
    for (int j = 0; fact[s[i] - '0'][j]; j++) {
      num.push_back(fact[s[i] - '0'][j]);
    }
  }
  sort(num.rbegin(), num.rend());
  for (int i = 0; i < num.size(); i++) {
    cout << num[i];
  }
  cout << endl;
}

```