#include <bits/stdc++.h>
using namespace std;
bool compare(long long a, long long b) { return a > b; }
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long t = 1;
  while (t-- > 0) {
    long long n;
    cin >> n;
    string str;
    cin >> str;
    vector<long long> arr(10, 0);
    long long temp;
    for (long long i = 0; i < n; i += 1) {
      temp = str[i] - 48;
      if (temp == 9) {
        arr[7] += 1;
        arr[3] += 2;
        arr[2] += 1;
      } else if (temp == 8) {
        arr[7] += 1;
        arr[2] += 3;
      } else if (temp == 7) {
        arr[7] += 1;
      } else if (temp == 6) {
        arr[5] += 1;
        arr[3] += 1;
      } else if (temp == 5) {
        arr[5] += 1;
      } else if (temp == 4) {
        arr[2] += 2;
        arr[3] += 1;
      } else if (temp == 3) {
        arr[3] += 1;
      } else if (temp == 2) {
        arr[2] += 1;
      }
    }
    for (long long i = 7; i >= 2; i -= 1) {
      for (long long j = 0; j < arr[i]; j += 1) {
        cout << i;
      }
    }
  }
  return 0;
}

### 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;
bool compare(long long a, long long b) { return a > b; }
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long t = 1;
  while (t-- > 0) {
    long long n;
    cin >> n;
    string str;
    cin >> str;
    vector<long long> arr(10, 0);
    long long temp;
    for (long long i = 0; i < n; i += 1) {
      temp = str[i] - 48;
      if (temp == 9) {
        arr[7] += 1;
        arr[3] += 2;
        arr[2] += 1;
      } else if (temp == 8) {
        arr[7] += 1;
        arr[2] += 3;
      } else if (temp == 7) {
        arr[7] += 1;
      } else if (temp == 6) {
        arr[5] += 1;
        arr[3] += 1;
      } else if (temp == 5) {
        arr[5] += 1;
      } else if (temp == 4) {
        arr[2] += 2;
        arr[3] += 1;
      } else if (temp == 3) {
        arr[3] += 1;
      } else if (temp == 2) {
        arr[2] += 1;
      }
    }
    for (long long i = 7; i >= 2; i -= 1) {
      for (long long j = 0; j < arr[i]; j += 1) {
        cout << i;
      }
    }
  }
  return 0;
}

```