#include <bits/stdc++.h>
using namespace std;
vector<int> ans;
int main() {
  string str;
  int i, j, n, p;
  while (cin >> n) {
    getchar();
    cin >> str;
    ans.clear();
    for (i = 0; i < n; i++) {
      if (str[i] == '0' || str[i] == '1') continue;
      p = str[i] - '0';
      switch (p) {
        case 2:
          ans.push_back(2);
          break;
        case 3:
          ans.push_back(3);
          break;
        case 5:
          ans.push_back(5);
          break;
        case 7:
          ans.push_back(7);
          break;
        case 4:
          ans.push_back(3);
          ans.push_back(2);
          ans.push_back(2);
          break;
        case 6:
          ans.push_back(5);
          ans.push_back(3);
          break;
        case 8:
          ans.push_back(7);
          ans.push_back(2);
          ans.push_back(2);
          ans.push_back(2);
          break;
        case 9:
          ans.push_back(7);
          ans.push_back(3);
          ans.push_back(3);
          ans.push_back(2);
          break;
      }
    }
    if (!ans.size()) ans.push_back(1);
    sort(ans.begin(), ans.end(), greater<int>());
    for (i = 0; i < ans.size(); i++) cout << ans[i];
    cout << endl;
  }
  return 0;
}

### Prompt

In CPP, your task is to solve 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;
vector<int> ans;
int main() {
  string str;
  int i, j, n, p;
  while (cin >> n) {
    getchar();
    cin >> str;
    ans.clear();
    for (i = 0; i < n; i++) {
      if (str[i] == '0' || str[i] == '1') continue;
      p = str[i] - '0';
      switch (p) {
        case 2:
          ans.push_back(2);
          break;
        case 3:
          ans.push_back(3);
          break;
        case 5:
          ans.push_back(5);
          break;
        case 7:
          ans.push_back(7);
          break;
        case 4:
          ans.push_back(3);
          ans.push_back(2);
          ans.push_back(2);
          break;
        case 6:
          ans.push_back(5);
          ans.push_back(3);
          break;
        case 8:
          ans.push_back(7);
          ans.push_back(2);
          ans.push_back(2);
          ans.push_back(2);
          break;
        case 9:
          ans.push_back(7);
          ans.push_back(3);
          ans.push_back(3);
          ans.push_back(2);
          break;
      }
    }
    if (!ans.size()) ans.push_back(1);
    sort(ans.begin(), ans.end(), greater<int>());
    for (i = 0; i < ans.size(); i++) cout << ans[i];
    cout << endl;
  }
  return 0;
}

```