#include <bits/stdc++.h>
using namespace std;
const int N = 5e5, M = 2000;
const int mod = 1e9 + 7;
const int inf = 0x3f3f3f3f;
const double pai = acos(-1);
int n;
string s, a;
long long f(long long x);
int main() {
  std::ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  ;
  cin >> n >> s;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == '4') {
      a += "322";
    } else if (s[i] == '8') {
      a += "2227";
    } else if (s[i] == '6') {
      a += "53";
    } else if (s[i] == '9') {
      s += "3327";
    } else if (s[i] != '1' && s[i] != '0')
      a += s[i];
  }
  sort(a.begin(), a.end(), greater<char>());
  cout << a;
}

### Prompt

Generate a cpp solution to 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;
const int N = 5e5, M = 2000;
const int mod = 1e9 + 7;
const int inf = 0x3f3f3f3f;
const double pai = acos(-1);
int n;
string s, a;
long long f(long long x);
int main() {
  std::ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  ;
  cin >> n >> s;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == '4') {
      a += "322";
    } else if (s[i] == '8') {
      a += "2227";
    } else if (s[i] == '6') {
      a += "53";
    } else if (s[i] == '9') {
      s += "3327";
    } else if (s[i] != '1' && s[i] != '0')
      a += s[i];
  }
  sort(a.begin(), a.end(), greater<char>());
  cout << a;
}

```