#include <bits/stdc++.h>
using namespace std;
string fact2_9(char n) {
  if (n == '2') return "2";
  if (n == '3') return "3";
  if (n == '4') return "322";
  if (n == '5') return "5";
  if (n == '6') return "53";
  if (n == '7') return "7";
  if (n == '8') return "7222";
  if (n == '9') return "7332";
  return "";
}
int main() {
  int n;
  string s, c = "";
  cin >> n >> s;
  for (int i = 0; i < s.length(); i++) c += fact2_9(s[i]);
  sort(c.begin(), c.begin() + c.length(), greater<char>());
  cout << c;
  return 0;
}

### 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;
string fact2_9(char n) {
  if (n == '2') return "2";
  if (n == '3') return "3";
  if (n == '4') return "322";
  if (n == '5') return "5";
  if (n == '6') return "53";
  if (n == '7') return "7";
  if (n == '8') return "7222";
  if (n == '9') return "7332";
  return "";
}
int main() {
  int n;
  string s, c = "";
  cin >> n >> s;
  for (int i = 0; i < s.length(); i++) c += fact2_9(s[i]);
  sort(c.begin(), c.begin() + c.length(), greater<char>());
  cout << c;
  return 0;
}

```