#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long k, n;
  cin >> k;
  string s;
  cin >> s;
  vector<int> v;
  for (int i = 0; i < k; ++i) {
    int a = s[i] - '0';
    if (a == 0 || a == 1)
      continue;
    else if (a == 2)
      v.push_back(2);
    else if (a == 3)
      v.push_back(3);
    else if (a == 4) {
      v.push_back(3);
      v.push_back(2);
      v.push_back(2);
    } else if (a == 5)
      v.push_back(5);
    else if (a == 6) {
      v.push_back(5);
      v.push_back(3);
    } else if (a == 7)
      v.push_back(7);
    else if (a == 8) {
      v.push_back(7);
      for (int i = 0; i < 3; ++i) v.push_back(2);
    } else {
      v.push_back(7);
      v.push_back(2);
      for (int i = 0; i < 2; ++i) v.push_back(3);
    }
  }
  sort(v.begin(), v.end());
  for (int i = (int)v.size() - 1; i >= 0; --i) {
    cout << v[i];
  }
  cout << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ;
  int t = 1;
  while (t--) {
    solve();
  }
}

### Prompt

Please provide a Cpp coded solution 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;
void solve() {
  long long k, n;
  cin >> k;
  string s;
  cin >> s;
  vector<int> v;
  for (int i = 0; i < k; ++i) {
    int a = s[i] - '0';
    if (a == 0 || a == 1)
      continue;
    else if (a == 2)
      v.push_back(2);
    else if (a == 3)
      v.push_back(3);
    else if (a == 4) {
      v.push_back(3);
      v.push_back(2);
      v.push_back(2);
    } else if (a == 5)
      v.push_back(5);
    else if (a == 6) {
      v.push_back(5);
      v.push_back(3);
    } else if (a == 7)
      v.push_back(7);
    else if (a == 8) {
      v.push_back(7);
      for (int i = 0; i < 3; ++i) v.push_back(2);
    } else {
      v.push_back(7);
      v.push_back(2);
      for (int i = 0; i < 2; ++i) v.push_back(3);
    }
  }
  sort(v.begin(), v.end());
  for (int i = (int)v.size() - 1; i >= 0; --i) {
    cout << v[i];
  }
  cout << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ;
  int t = 1;
  while (t--) {
    solve();
  }
}

```