#include <bits/stdc++.h>
using namespace std;
long n;
string s, x;
long a[9];
int main() {
  cin >> n >> s;
  while (s[0] == '0') {
    s.replace(0, 1, "");
    n--;
  }
  for (int i = 0; i < n; i++) {
    int m;
    m = s[i] - 48;
    for (int j = 2; j <= m; j++) {
      if (j == 2) a[2]++;
      if (j == 3) {
        a[3]++;
        a[2]--;
      }
      if (j == 4) a[2] += 2;
      if (j == 5) {
        a[5]++;
        a[3]--;
        a[2] -= 2;
      }
      if (j == 6) a[3]++;
      if (j == 7) {
        a[7]++;
        a[3]--;
        a[5]--;
      }
      if (j == 8) a[2] += 3;
      if (j == 9) {
        a[3] += 2;
        a[2] -= 2;
      }
    }
  }
  x = "";
  for (int i = 7; i > 1; i--)
    if (a[i] > 0)
      for (int j = 1; j <= a[i]; j++) x += i + '0';
  cout << x;
}

### 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;
long n;
string s, x;
long a[9];
int main() {
  cin >> n >> s;
  while (s[0] == '0') {
    s.replace(0, 1, "");
    n--;
  }
  for (int i = 0; i < n; i++) {
    int m;
    m = s[i] - 48;
    for (int j = 2; j <= m; j++) {
      if (j == 2) a[2]++;
      if (j == 3) {
        a[3]++;
        a[2]--;
      }
      if (j == 4) a[2] += 2;
      if (j == 5) {
        a[5]++;
        a[3]--;
        a[2] -= 2;
      }
      if (j == 6) a[3]++;
      if (j == 7) {
        a[7]++;
        a[3]--;
        a[5]--;
      }
      if (j == 8) a[2] += 3;
      if (j == 9) {
        a[3] += 2;
        a[2] -= 2;
      }
    }
  }
  x = "";
  for (int i = 7; i > 1; i--)
    if (a[i] > 0)
      for (int j = 1; j <= a[i]; j++) x += i + '0';
  cout << x;
}

```