#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  long long int x;
  cin >> x;
  long long int n;
  cin >> n;
  vector<long long int> v;
  while (n > 0) {
    v.push_back(n % 10);
    n /= 10;
  }
  vector<long long int> vv;
  for (auto x : v) {
    if (x == 4) {
      vv.push_back(2);
      vv.push_back(2);
      vv.push_back(3);
    } else {
      if (x == 8) {
        vv.push_back(2);
        vv.push_back(2);
        vv.push_back(2);
        vv.push_back(7);
      } else {
        if (x == 6) {
          vv.push_back(5);
          vv.push_back(3);
        } else {
          if (x == 9) {
            vv.push_back(3);
            vv.push_back(3);
            vv.push_back(2);
            vv.push_back(7);
          } else {
            if (x != 0 && x != 1) vv.push_back(x);
          }
        }
      }
    }
  }
  sort(vv.begin(), vv.end(), greater<long long int>());
  for (auto x : vv) cout << x;
  cout << "\n";
}

### Prompt

Create a solution in CPP for 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;
int32_t main() {
  long long int x;
  cin >> x;
  long long int n;
  cin >> n;
  vector<long long int> v;
  while (n > 0) {
    v.push_back(n % 10);
    n /= 10;
  }
  vector<long long int> vv;
  for (auto x : v) {
    if (x == 4) {
      vv.push_back(2);
      vv.push_back(2);
      vv.push_back(3);
    } else {
      if (x == 8) {
        vv.push_back(2);
        vv.push_back(2);
        vv.push_back(2);
        vv.push_back(7);
      } else {
        if (x == 6) {
          vv.push_back(5);
          vv.push_back(3);
        } else {
          if (x == 9) {
            vv.push_back(3);
            vv.push_back(3);
            vv.push_back(2);
            vv.push_back(7);
          } else {
            if (x != 0 && x != 1) vv.push_back(x);
          }
        }
      }
    }
  }
  sort(vv.begin(), vv.end(), greater<long long int>());
  for (auto x : vv) cout << x;
  cout << "\n";
}

```