#include <bits/stdc++.h>
using namespace std;
bool cmp(char x, char y) { return x > y; }
char a[16];
char s[105];
int main() {
  int n;
  while (~scanf("%d", &n)) {
    scanf("%s", a);
    memset(s, 0, sizeof(s));
    int k = 0;
    for (int i = 0; i < n; i++) {
      if (a[i] == '4') {
        s[k++] = '3';
        s[k++] = '2';
        s[k++] = '2';
      } else if (a[i] == '6') {
        s[k++] = '5';
        s[k++] = '3';
      } else if (a[i] == '8') {
        s[k++] = '7';
        s[k++] = '2';
        s[k++] = '2';
        s[k++] = '2';
      } else if (a[i] == '9') {
        s[k++] = '7';
        s[k++] = '3';
        s[k++] = '3';
        s[k++] = '2';
      } else if (a[i] != '1' && a[i] != '0')
        s[k++] = a[i];
    }
    sort(s, s + k, cmp);
    puts(s);
  }
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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;
bool cmp(char x, char y) { return x > y; }
char a[16];
char s[105];
int main() {
  int n;
  while (~scanf("%d", &n)) {
    scanf("%s", a);
    memset(s, 0, sizeof(s));
    int k = 0;
    for (int i = 0; i < n; i++) {
      if (a[i] == '4') {
        s[k++] = '3';
        s[k++] = '2';
        s[k++] = '2';
      } else if (a[i] == '6') {
        s[k++] = '5';
        s[k++] = '3';
      } else if (a[i] == '8') {
        s[k++] = '7';
        s[k++] = '2';
        s[k++] = '2';
        s[k++] = '2';
      } else if (a[i] == '9') {
        s[k++] = '7';
        s[k++] = '3';
        s[k++] = '3';
        s[k++] = '2';
      } else if (a[i] != '1' && a[i] != '0')
        s[k++] = a[i];
    }
    sort(s, s + k, cmp);
    puts(s);
  }
}

```