#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  vector<int> a(10, 0);
  for (int i = 0; i < s.length(); ++i) {
    int curr = s[i] - '0';
    if (curr == 2) {
      ++a[2];
    }
    if (curr == 3) {
      ++a[2];
      ++a[3];
    }
    if (curr == 4) {
      a[2] += 3;
      ++a[3];
    }
    if (curr == 5) {
      a[2] += 3;
      ++a[3];
      ++a[5];
    }
    if (curr == 6) {
      a[2] += 4;
      a[3] += 2;
      ++a[5];
    }
    if (curr == 7) {
      a[2] += 4;
      a[3] += 2;
      ++a[5];
      ++a[7];
    }
    if (curr == 8) {
      a[2] += 7;
      a[3] += 2;
      ++a[5];
      ++a[7];
    }
    if (curr == 9) {
      a[2] += 7;
      a[3] += 4;
      ++a[5];
      ++a[7];
    }
  }
  string ans = "";
  for (int i = 0; i < a[7]; ++i) ans += "7";
  a[2] -= 4 * a[7];
  a[3] -= 2 * a[7];
  a[5] -= a[7];
  a[7] = 0;
  for (int i = 0; i < a[5]; ++i) ans += "5";
  a[2] -= 3 * a[5];
  a[3] -= a[5];
  a[5] = 0;
  for (int i = 0; i < a[3]; ++i) ans += "3";
  a[2] -= a[3];
  for (int i = 0; i < a[2]; ++i) ans += "2";
  cout << ans << endl;
}

### Prompt

Develop a solution in CPP 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;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  vector<int> a(10, 0);
  for (int i = 0; i < s.length(); ++i) {
    int curr = s[i] - '0';
    if (curr == 2) {
      ++a[2];
    }
    if (curr == 3) {
      ++a[2];
      ++a[3];
    }
    if (curr == 4) {
      a[2] += 3;
      ++a[3];
    }
    if (curr == 5) {
      a[2] += 3;
      ++a[3];
      ++a[5];
    }
    if (curr == 6) {
      a[2] += 4;
      a[3] += 2;
      ++a[5];
    }
    if (curr == 7) {
      a[2] += 4;
      a[3] += 2;
      ++a[5];
      ++a[7];
    }
    if (curr == 8) {
      a[2] += 7;
      a[3] += 2;
      ++a[5];
      ++a[7];
    }
    if (curr == 9) {
      a[2] += 7;
      a[3] += 4;
      ++a[5];
      ++a[7];
    }
  }
  string ans = "";
  for (int i = 0; i < a[7]; ++i) ans += "7";
  a[2] -= 4 * a[7];
  a[3] -= 2 * a[7];
  a[5] -= a[7];
  a[7] = 0;
  for (int i = 0; i < a[5]; ++i) ans += "5";
  a[2] -= 3 * a[5];
  a[3] -= a[5];
  a[5] = 0;
  for (int i = 0; i < a[3]; ++i) ans += "3";
  a[2] -= a[3];
  for (int i = 0; i < a[2]; ++i) ans += "2";
  cout << ans << endl;
}

```