#include <bits/stdc++.h>
using namespace std;
int main(void) {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  string s;
  cin >> s;
  priority_queue<string> max_heap;
  for (int i = 0; i < n; i++) {
    string s2;
    s2 = s.substr(i, 1);
    max_heap.push(s2);
  }
  vector<string> out_;
  while (!max_heap.empty()) {
    string t = max_heap.top();
    max_heap.pop();
    if (t == "9") {
      out_.push_back("2");
      out_.push_back("3");
      out_.push_back("3");
      max_heap.push("7");
    } else if (t == "8") {
      out_.push_back("2");
      out_.push_back("2");
      out_.push_back("2");
      max_heap.push("7");
    } else if (t == "6") {
      out_.push_back("3");
      max_heap.push("5");
    } else if (t == "4") {
      out_.push_back("2");
      out_.push_back("2");
      max_heap.push("3");
    } else {
      if (t != "0" && t != "1") out_.push_back(t);
    }
  }
  sort(out_.begin(), out_.end(), greater<string>());
  string ans = "";
  for (string &k : out_) ans = ans + k;
  cout << ans << "\n";
  return 0;
}

### 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;
int main(void) {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  string s;
  cin >> s;
  priority_queue<string> max_heap;
  for (int i = 0; i < n; i++) {
    string s2;
    s2 = s.substr(i, 1);
    max_heap.push(s2);
  }
  vector<string> out_;
  while (!max_heap.empty()) {
    string t = max_heap.top();
    max_heap.pop();
    if (t == "9") {
      out_.push_back("2");
      out_.push_back("3");
      out_.push_back("3");
      max_heap.push("7");
    } else if (t == "8") {
      out_.push_back("2");
      out_.push_back("2");
      out_.push_back("2");
      max_heap.push("7");
    } else if (t == "6") {
      out_.push_back("3");
      max_heap.push("5");
    } else if (t == "4") {
      out_.push_back("2");
      out_.push_back("2");
      max_heap.push("3");
    } else {
      if (t != "0" && t != "1") out_.push_back(t);
    }
  }
  sort(out_.begin(), out_.end(), greater<string>());
  string ans = "";
  for (string &k : out_) ans = ans + k;
  cout << ans << "\n";
  return 0;
}

```