#include <bits/stdc++.h>
using namespace std;
const int N = 10010;
int main() {
  int t;
  cin >> t;
  string str1, str2 = "";
  cin >> str1;
  for (int i = 0; i < str1.size(); i++) {
    if (str1[i] == '2') str2 += "2";
    if (str1[i] == '3') str2 += "3";
    if (str1[i] == '4') str2 += "322";
    if (str1[i] == '5') str2 += "5";
    if (str1[i] == '6') str2 += "53";
    if (str1[i] == '7') str2 += "7";
    if (str1[i] == '8') str2 += "7222";
    if (str1[i] == '9') str2 += "7332";
  }
  sort(str2.begin(), str2.end());
  reverse(str2.begin(), str2.end());
  cout << str2 << endl;
}

### Prompt

Your challenge is to write a cpp solution 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;
const int N = 10010;
int main() {
  int t;
  cin >> t;
  string str1, str2 = "";
  cin >> str1;
  for (int i = 0; i < str1.size(); i++) {
    if (str1[i] == '2') str2 += "2";
    if (str1[i] == '3') str2 += "3";
    if (str1[i] == '4') str2 += "322";
    if (str1[i] == '5') str2 += "5";
    if (str1[i] == '6') str2 += "53";
    if (str1[i] == '7') str2 += "7";
    if (str1[i] == '8') str2 += "7222";
    if (str1[i] == '9') str2 += "7332";
  }
  sort(str2.begin(), str2.end());
  reverse(str2.begin(), str2.end());
  cout << str2 << endl;
}

```