#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string str;
  cin >> str;
  map<char, int> M;
  for (int i = 0; i < str.length(); ++i) {
    if (str[i] == '2' || str[i] == '3' || str[i] == '5' || str[i] == '7') {
      M[str[i]]++;
    } else if (str[i] == '4') {
      M['2'] += 2;
      M['3'] += 1;
    } else if (str[i] == '6') {
      M['5']++;
      M['3']++;
    } else if (str[i] == '8') {
      M['2'] += 3;
      M['7'] += 1;
    } else if (str[i] == '9') {
      M['7'] += 1;
      M['2'] += 1;
      M['3'] += 2;
    }
  }
  for (char ch = '9'; ch > '1'; ch--) {
    for (int i = 0; i < M[ch]; ++i) {
      cout << ch;
    }
  }
  cout << endl;
  return 0;
}

### Prompt

Construct a cpp code solution to the problem outlined:

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;
  string str;
  cin >> str;
  map<char, int> M;
  for (int i = 0; i < str.length(); ++i) {
    if (str[i] == '2' || str[i] == '3' || str[i] == '5' || str[i] == '7') {
      M[str[i]]++;
    } else if (str[i] == '4') {
      M['2'] += 2;
      M['3'] += 1;
    } else if (str[i] == '6') {
      M['5']++;
      M['3']++;
    } else if (str[i] == '8') {
      M['2'] += 3;
      M['7'] += 1;
    } else if (str[i] == '9') {
      M['7'] += 1;
      M['2'] += 1;
      M['3'] += 2;
    }
  }
  for (char ch = '9'; ch > '1'; ch--) {
    for (int i = 0; i < M[ch]; ++i) {
      cout << ch;
    }
  }
  cout << endl;
  return 0;
}

```