#include <bits/stdc++.h>
using namespace std;
int tail;
int temp[60];
void insert(int n) {
  switch (n) {
    case 0:
      break;
    case 1:
      break;
    case 2:
      temp[tail++] = 2;
      break;
    case 3:
      temp[tail++] = 3;
      break;
    case 4:
      temp[tail++] = 3;
      temp[tail++] = 2;
      temp[tail++] = 2;
      break;
    case 5:
      temp[tail++] = 5;
      break;
    case 6:
      temp[tail++] = 5;
      temp[tail++] = 3;
      break;
    case 7:
      temp[tail++] = 7;
      break;
    case 8:
      temp[tail++] = 7;
      temp[tail++] = 2;
      temp[tail++] = 2;
      temp[tail++] = 2;
      break;
    case 9:
      temp[tail++] = 7;
      temp[tail++] = 3;
      temp[tail++] = 3;
      temp[tail++] = 2;
  }
}
bool comp(int a, int b) { return a > b; }
int main() {
  string a;
  cin >> a;
  cin >> a;
  for (int i = 0; i < a.length(); i++) {
    insert(a[i] - 48);
  }
  sort(temp, temp + tail, comp);
  for (int i = 0; i < tail; i++) {
    cout << temp[i];
  }
}

### Prompt

Generate a Cpp solution to 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 tail;
int temp[60];
void insert(int n) {
  switch (n) {
    case 0:
      break;
    case 1:
      break;
    case 2:
      temp[tail++] = 2;
      break;
    case 3:
      temp[tail++] = 3;
      break;
    case 4:
      temp[tail++] = 3;
      temp[tail++] = 2;
      temp[tail++] = 2;
      break;
    case 5:
      temp[tail++] = 5;
      break;
    case 6:
      temp[tail++] = 5;
      temp[tail++] = 3;
      break;
    case 7:
      temp[tail++] = 7;
      break;
    case 8:
      temp[tail++] = 7;
      temp[tail++] = 2;
      temp[tail++] = 2;
      temp[tail++] = 2;
      break;
    case 9:
      temp[tail++] = 7;
      temp[tail++] = 3;
      temp[tail++] = 3;
      temp[tail++] = 2;
  }
}
bool comp(int a, int b) { return a > b; }
int main() {
  string a;
  cin >> a;
  cin >> a;
  for (int i = 0; i < a.length(); i++) {
    insert(a[i] - 48);
  }
  sort(temp, temp + tail, comp);
  for (int i = 0; i < tail; i++) {
    cout << temp[i];
  }
}

```