#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  string s, str;
  cin >> s;
  for (long long int i = 0; i < s.size(); i++) {
    if (s[i] == '4')
      str += "322";
    else if (s[i] == '6')
      str += "53";
    else if (s[i] == '8')
      str += "7222";
    else if (s[i] == '9')
      str += "7332";
    else if (s[i] >= '2' and s[i] <= '9')
      str += s[i];
  }
  sort(str.begin(), str.end(), greater<char>());
  for (long long int i = 0; i < str.size(); i++) cout << str[i];
}

### 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;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  string s, str;
  cin >> s;
  for (long long int i = 0; i < s.size(); i++) {
    if (s[i] == '4')
      str += "322";
    else if (s[i] == '6')
      str += "53";
    else if (s[i] == '8')
      str += "7222";
    else if (s[i] == '9')
      str += "7332";
    else if (s[i] >= '2' and s[i] <= '9')
      str += s[i];
  }
  sort(str.begin(), str.end(), greater<char>());
  for (long long int i = 0; i < str.size(); i++) cout << str[i];
}

```