#include <bits/stdc++.h>
using namespace std;
int main() {
  string s, s2;
  int a;
  cin >> a;
  cin >> s;
  string s1[] = {"", "", "2", "3", "223", "5", "35", "7", "2227", "2337"};
  for (int i = 0; i < s.size(); i++) {
    s2 += s1[s[i] - '0'];
  }
  sort(s2.begin(), s2.end());
  reverse(s2.begin(), s2.end());
  cout << s2 << endl;
  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;
int main() {
  string s, s2;
  int a;
  cin >> a;
  cin >> s;
  string s1[] = {"", "", "2", "3", "223", "5", "35", "7", "2227", "2337"};
  for (int i = 0; i < s.size(); i++) {
    s2 += s1[s[i] - '0'];
  }
  sort(s2.begin(), s2.end());
  reverse(s2.begin(), s2.end());
  cout << s2 << endl;
  return 0;
}

```