#include <bits/stdc++.h>
using namespace std;
unsigned long long fakultaet(unsigned long long n) {
  return (n == 1 || n == 0) ? 1 : fakultaet(n - 1) * n;
}
int main() {
  ios_base::sync_with_stdio(false);
  string n, a;
  cin >> n >> a;
  vector<long long> result;
  for (long long i = (0); i < ((long long)a.length()); i++) {
    if (a.at(i) == '9') {
      result.push_back(7);
      result.push_back(3);
      result.push_back(3);
      result.push_back(2);
    }
    if (a.at(i) == '8') {
      result.push_back(7);
      result.push_back(2);
      result.push_back(2);
      result.push_back(2);
    }
    if (a.at(i) == '7') {
      result.push_back(7);
    }
    if (a.at(i) == '6') {
      result.push_back(5);
      result.push_back(3);
    }
    if (a.at(i) == '5') {
      result.push_back(5);
    }
    if (a.at(i) == '4') {
      result.push_back(3);
      result.push_back(2);
      result.push_back(2);
    }
    if (a.at(i) == '3') {
      result.push_back(3);
    }
    if (a.at(i) == '2') {
      result.push_back(2);
    }
  }
  sort(result.begin(), result.end());
  for (long long i = (result.size()) - 1; i >= (0); i--) {
    cout << result[i];
  }
  cout << endl;
}

### Prompt

Generate 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;
unsigned long long fakultaet(unsigned long long n) {
  return (n == 1 || n == 0) ? 1 : fakultaet(n - 1) * n;
}
int main() {
  ios_base::sync_with_stdio(false);
  string n, a;
  cin >> n >> a;
  vector<long long> result;
  for (long long i = (0); i < ((long long)a.length()); i++) {
    if (a.at(i) == '9') {
      result.push_back(7);
      result.push_back(3);
      result.push_back(3);
      result.push_back(2);
    }
    if (a.at(i) == '8') {
      result.push_back(7);
      result.push_back(2);
      result.push_back(2);
      result.push_back(2);
    }
    if (a.at(i) == '7') {
      result.push_back(7);
    }
    if (a.at(i) == '6') {
      result.push_back(5);
      result.push_back(3);
    }
    if (a.at(i) == '5') {
      result.push_back(5);
    }
    if (a.at(i) == '4') {
      result.push_back(3);
      result.push_back(2);
      result.push_back(2);
    }
    if (a.at(i) == '3') {
      result.push_back(3);
    }
    if (a.at(i) == '2') {
      result.push_back(2);
    }
  }
  sort(result.begin(), result.end());
  for (long long i = (result.size()) - 1; i >= (0); i--) {
    cout << result[i];
  }
  cout << endl;
}

```