#include <bits/stdc++.h>
using namespace std;
long long ans = 0, i = 0, j = 0, cnt = 0, sum = 0;
long long arr[51];
long long brr[51];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) {
    int n;
    cin >> n;
    string a;
    cin >> a;
    string s = "";
    for (i = 0; i < n; i++) {
      if (a[i] == '0' || a[i] == '1')
        continue;
      else if (a[i] == '4')
        s += "322";
      else if (a[i] == '6') {
        s += "53";
      } else if (a[i] == '8')
        s += "7222";
      else if (a[i] == '9')
        s += "7332";
      else
        s += a[i];
    }
    sort((s).begin(), (s).end());
    reverse((s).begin(), (s).end());
    cout << s << "\n";
  }
}

### Prompt

Develop a solution in CPP 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;
long long ans = 0, i = 0, j = 0, cnt = 0, sum = 0;
long long arr[51];
long long brr[51];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) {
    int n;
    cin >> n;
    string a;
    cin >> a;
    string s = "";
    for (i = 0; i < n; i++) {
      if (a[i] == '0' || a[i] == '1')
        continue;
      else if (a[i] == '4')
        s += "322";
      else if (a[i] == '6') {
        s += "53";
      } else if (a[i] == '8')
        s += "7222";
      else if (a[i] == '9')
        s += "7332";
      else
        s += a[i];
    }
    sort((s).begin(), (s).end());
    reverse((s).begin(), (s).end());
    cout << s << "\n";
  }
}

```