#include <bits/stdc++.h>
using namespace std;
int main() {
  int n = 0;
  cin >> n;
  int two = 0;
  int three = 0;
  int five = 0;
  int seven = 0;
  for (int i = 0; i < n; ++i) {
    char digit = '\0';
    cin >> digit;
    switch (digit) {
      case '9':
        three += 2;
      case '8':
        two += 3;
      case '7':
        seven += 1;
      case '6':
        two += 1;
        three += 1;
      case '5':
        five += 1;
      case '4':
        two += 2;
      case '3':
        three += 1;
      case '2':
        two += 1;
      default:
        break;
    }
  }
  auto withdraw = [&](int digit) {
    switch (digit) {
      case 9:
        three -= 2;
      case 8:
        two -= 3;
      case 7:
        seven -= 1;
      case 6:
        two -= 1;
        three -= 1;
      case 5:
        five -= 1;
      case 4:
        two -= 2;
      case 3:
        three -= 1;
      case 2:
        two -= 1;
      default:
        break;
    }
  };
  while (seven) {
    cout << '7';
    withdraw(7);
  }
  while (five) {
    cout << '5';
    withdraw(5);
  }
  while (three) {
    cout << '3';
    withdraw(3);
  }
  while (two) {
    cout << '2';
    withdraw(2);
  }
  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;
int main() {
  int n = 0;
  cin >> n;
  int two = 0;
  int three = 0;
  int five = 0;
  int seven = 0;
  for (int i = 0; i < n; ++i) {
    char digit = '\0';
    cin >> digit;
    switch (digit) {
      case '9':
        three += 2;
      case '8':
        two += 3;
      case '7':
        seven += 1;
      case '6':
        two += 1;
        three += 1;
      case '5':
        five += 1;
      case '4':
        two += 2;
      case '3':
        three += 1;
      case '2':
        two += 1;
      default:
        break;
    }
  }
  auto withdraw = [&](int digit) {
    switch (digit) {
      case 9:
        three -= 2;
      case 8:
        two -= 3;
      case 7:
        seven -= 1;
      case 6:
        two -= 1;
        three -= 1;
      case 5:
        five -= 1;
      case 4:
        two -= 2;
      case 3:
        three -= 1;
      case 2:
        two -= 1;
      default:
        break;
    }
  };
  while (seven) {
    cout << '7';
    withdraw(7);
  }
  while (five) {
    cout << '5';
    withdraw(5);
  }
  while (three) {
    cout << '3';
    withdraw(3);
  }
  while (two) {
    cout << '2';
    withdraw(2);
  }
  cout << endl;
}

```