#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a[5] = {0}, i, j, z = 0, x = 0, y = 0;
  char q;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> q;
    if (q == '5') {
      z++;
    } else if (q == '7') {
      x++;
    } else if (q == '9') {
      y += 2;
      a[2]++;
      x++;
    } else if (q == '8') {
      a[2] += 3;
      x++;
    } else if (q == '6') {
      y++;
      z++;
    } else if (q == '4') {
      a[2] += 2;
      y++;
    } else if (q == '3') {
      y++;
    } else if (q == '2') {
      a[2]++;
    }
  }
  for (i = 0; i < x; i++) {
    cout << 7;
  }
  for (i = 0; i < z; i++) {
    cout << 5;
  }
  if (a[3] != 0) {
    for (;;)
      ;
  }
  for (i = 0; i < y; i++) {
    cout << 3;
  }
  for (i = 0; i < a[2]; i++) {
    cout << 2;
  }
  return 0;
}

### Prompt

Please provide a CPP coded solution to the problem described below:

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, a[5] = {0}, i, j, z = 0, x = 0, y = 0;
  char q;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> q;
    if (q == '5') {
      z++;
    } else if (q == '7') {
      x++;
    } else if (q == '9') {
      y += 2;
      a[2]++;
      x++;
    } else if (q == '8') {
      a[2] += 3;
      x++;
    } else if (q == '6') {
      y++;
      z++;
    } else if (q == '4') {
      a[2] += 2;
      y++;
    } else if (q == '3') {
      y++;
    } else if (q == '2') {
      a[2]++;
    }
  }
  for (i = 0; i < x; i++) {
    cout << 7;
  }
  for (i = 0; i < z; i++) {
    cout << 5;
  }
  if (a[3] != 0) {
    for (;;)
      ;
  }
  for (i = 0; i < y; i++) {
    cout << 3;
  }
  for (i = 0; i < a[2]; i++) {
    cout << 2;
  }
  return 0;
}

```