#include <bits/stdc++.h>
using namespace std;
int w, m, k, h, y, u, n, x, sum, mx = 0, a[111], b, c, r, l, d;
string s;
char f[60];
int main() {
  cin >> n;
  cin >> s;
  int j = 0;
  for (int i = 0; i < n; i++) {
    if (s[i] == '2') {
      f[j] = '2';
      j++;
    }
    if (s[i] == '3') {
      f[j] = '3';
      j++;
    }
    if (s[i] == '4') {
      f[j] = '3';
      ++j;
      f[j] = '2';
      ++j;
      f[j] = '2';
      ++j;
    }
    if (s[i] == '5') {
      f[j] = '5';
      j++;
    }
    if (s[i] == '6') {
      f[j] = '5';
      ++j;
      f[j] = '3';
      j++;
    }
    if (s[i] == '7') {
      f[j] = '7';
      j++;
    }
    if (s[i] == '8') {
      f[j] = '7';
      ++j;
      f[j] = '2';
      ++j;
      f[j] = '2';
      ++j;
      f[j] = '2';
      ++j;
    }
    if (s[i] == '9') {
      f[j] = '7';
      ++j;
      f[j] = '3';
      ++j;
      f[j] = '3';
      ++j;
      f[j] = '2';
      ++j;
    }
  }
  sort(f, f + j);
  reverse(f, f + j);
  for (int i = 0; i < j; i++) cout << f[i];
  return 0;
}

### Prompt

Your task is to create 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 w, m, k, h, y, u, n, x, sum, mx = 0, a[111], b, c, r, l, d;
string s;
char f[60];
int main() {
  cin >> n;
  cin >> s;
  int j = 0;
  for (int i = 0; i < n; i++) {
    if (s[i] == '2') {
      f[j] = '2';
      j++;
    }
    if (s[i] == '3') {
      f[j] = '3';
      j++;
    }
    if (s[i] == '4') {
      f[j] = '3';
      ++j;
      f[j] = '2';
      ++j;
      f[j] = '2';
      ++j;
    }
    if (s[i] == '5') {
      f[j] = '5';
      j++;
    }
    if (s[i] == '6') {
      f[j] = '5';
      ++j;
      f[j] = '3';
      j++;
    }
    if (s[i] == '7') {
      f[j] = '7';
      j++;
    }
    if (s[i] == '8') {
      f[j] = '7';
      ++j;
      f[j] = '2';
      ++j;
      f[j] = '2';
      ++j;
      f[j] = '2';
      ++j;
    }
    if (s[i] == '9') {
      f[j] = '7';
      ++j;
      f[j] = '3';
      ++j;
      f[j] = '3';
      ++j;
      f[j] = '2';
      ++j;
    }
  }
  sort(f, f + j);
  reverse(f, f + j);
  for (int i = 0; i < j; i++) cout << f[i];
  return 0;
}

```