#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n;
  string s;
  cin >> n >> s;
  map<int, int> mem;
  for (int i = 0; i < (n); i++) {
    int c = s[i] - '0';
    switch (c) {
      case 0:
        break;
      case 1:
        break;
      case 2:
        mem[2]++;
        break;
      case 3:
        mem[3]++;
        mem[2]++;
        break;
      case 4:
        mem[2] += 3;
        mem[3]++;
        break;
      case 5:
        mem[5]++;
        mem[2] += 3;
        mem[3]++;
        break;
      case 6:
        mem[5]++;
        mem[2] += 4;
        mem[3] += 2;
        break;
      case 7:
        mem[7]++;
        mem[5]++;
        mem[2] += 4;
        mem[3] += 2;
        break;
      case 8:
        mem[7]++;
        mem[5]++;
        mem[2] += 7;
        mem[3] += 2;
        break;
      case 9:
        mem[7]++;
        mem[5]++;
        mem[2] += 7;
        mem[3] += 4;
        break;
    }
  }
  string ans = "";
  while (mem[7] > 0) {
    ans += '7';
    mem[7]--;
    mem[5]--;
    mem[2] -= 4;
    mem[3] -= 2;
  }
  while (mem[5] > 0) {
    ans += '5';
    mem[5]--;
    mem[2] -= 3;
    mem[3]--;
  }
  while (mem[3] > 0) {
    ans += '3';
    mem[3]--;
    mem[2]--;
  }
  while (mem[2] > 0) {
    ans += '2';
    mem[2]--;
  }
  cout << ans << endl;
}

### Prompt

In cpp, your task is to solve 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() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n;
  string s;
  cin >> n >> s;
  map<int, int> mem;
  for (int i = 0; i < (n); i++) {
    int c = s[i] - '0';
    switch (c) {
      case 0:
        break;
      case 1:
        break;
      case 2:
        mem[2]++;
        break;
      case 3:
        mem[3]++;
        mem[2]++;
        break;
      case 4:
        mem[2] += 3;
        mem[3]++;
        break;
      case 5:
        mem[5]++;
        mem[2] += 3;
        mem[3]++;
        break;
      case 6:
        mem[5]++;
        mem[2] += 4;
        mem[3] += 2;
        break;
      case 7:
        mem[7]++;
        mem[5]++;
        mem[2] += 4;
        mem[3] += 2;
        break;
      case 8:
        mem[7]++;
        mem[5]++;
        mem[2] += 7;
        mem[3] += 2;
        break;
      case 9:
        mem[7]++;
        mem[5]++;
        mem[2] += 7;
        mem[3] += 4;
        break;
    }
  }
  string ans = "";
  while (mem[7] > 0) {
    ans += '7';
    mem[7]--;
    mem[5]--;
    mem[2] -= 4;
    mem[3] -= 2;
  }
  while (mem[5] > 0) {
    ans += '5';
    mem[5]--;
    mem[2] -= 3;
    mem[3]--;
  }
  while (mem[3] > 0) {
    ans += '3';
    mem[3]--;
    mem[2]--;
  }
  while (mem[2] > 0) {
    ans += '2';
    mem[2]--;
  }
  cout << ans << endl;
}

```