#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, nm;
  vector<string> a(10);
  string s = "";
  a[2] = "2";
  a[3] = "3";
  a[4] = "322";
  a[5] = "5";
  a[6] = "53";
  a[7] = "7";
  a[8] = "7222";
  a[9] = "7332";
  cin >> n >> nm;
  stringstream ss;
  ss << nm;
  string str = ss.str();
  int l = str.size();
  for (int i = 0; i < l; i++) {
    if (str[i] == '0' || str[i] == '1')
      continue;
    else {
      stringstream ss;
      ss << str[i];
      long long indx;
      ss >> indx;
      s = s + a[indx];
    }
  }
  sort(s.begin(), s.end(), greater<int>());
  cout << s << endl;
  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() {
  long long n, nm;
  vector<string> a(10);
  string s = "";
  a[2] = "2";
  a[3] = "3";
  a[4] = "322";
  a[5] = "5";
  a[6] = "53";
  a[7] = "7";
  a[8] = "7222";
  a[9] = "7332";
  cin >> n >> nm;
  stringstream ss;
  ss << nm;
  string str = ss.str();
  int l = str.size();
  for (int i = 0; i < l; i++) {
    if (str[i] == '0' || str[i] == '1')
      continue;
    else {
      stringstream ss;
      ss << str[i];
      long long indx;
      ss >> indx;
      s = s + a[indx];
    }
  }
  sort(s.begin(), s.end(), greater<int>());
  cout << s << endl;
  return 0;
}

```