#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n;
  cin >> n;
  string s;
  cin >> s;
  int arr[10];
  for (int(i) = 0; (i) < (10); (i)++) {
    arr[i] = 0;
  }
  for (int(i) = 0; (i) < (n); (i)++) {
    if (s[i] == '2') {
      arr[2]++;
    }
    if (s[i] == '3') {
      arr[3]++;
    }
    if (s[i] == '4') {
      arr[2] += 2;
      arr[3]++;
    }
    if (s[i] == '5') {
      arr[5]++;
    }
    if (s[i] == '6') {
      arr[5]++;
      arr[3]++;
    }
    if (s[i] == '7') {
      arr[7]++;
    }
    if (s[i] == '8') {
      arr[7]++;
      arr[2] += 3;
    }
    if (s[i] == '9') {
      arr[3] += 2;
      arr[7]++;
      arr[2]++;
    }
  }
  for (int(i) = (9); (i) >= (2); (i)--) {
    for (int(j) = 0; (j) < (arr[i]); (j)++) {
      cout << i;
    }
  }
  cout << endl;
}

### Prompt

Create a solution in CPP for 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() {
  long long int n;
  cin >> n;
  string s;
  cin >> s;
  int arr[10];
  for (int(i) = 0; (i) < (10); (i)++) {
    arr[i] = 0;
  }
  for (int(i) = 0; (i) < (n); (i)++) {
    if (s[i] == '2') {
      arr[2]++;
    }
    if (s[i] == '3') {
      arr[3]++;
    }
    if (s[i] == '4') {
      arr[2] += 2;
      arr[3]++;
    }
    if (s[i] == '5') {
      arr[5]++;
    }
    if (s[i] == '6') {
      arr[5]++;
      arr[3]++;
    }
    if (s[i] == '7') {
      arr[7]++;
    }
    if (s[i] == '8') {
      arr[7]++;
      arr[2] += 3;
    }
    if (s[i] == '9') {
      arr[3] += 2;
      arr[7]++;
      arr[2]++;
    }
  }
  for (int(i) = (9); (i) >= (2); (i)--) {
    for (int(j) = 0; (j) < (arr[i]); (j)++) {
      cout << i;
    }
  }
  cout << endl;
}

```