#include <bits/stdc++.h>
using namespace std;
int digit[12], arr2[20], res[100000];
char arr1[20];
bool compare(int a, int b) {
  if (a > b)
    return true;
  else
    return false;
}
int main() {
  int n, i, j, index = 0, size = 0;
  cin >> n;
  scanf("%s", arr1);
  memset(digit, 0, sizeof(digit));
  memset(res, 0, sizeof(res));
  for (i = 0; i < n; i++) {
    arr2[i] = arr1[i] - '0';
  }
  for (i = 0; i < n; i++) {
    switch (arr2[i] % 10) {
      case 2:
        digit[2]++;
        break;
      case 3:
        digit[3]++;
        break;
      case 4:
        digit[2] += 2;
        digit[3]++;
        break;
      case 5:
        digit[5]++;
        break;
      case 6:
        digit[3]++;
        digit[5]++;
        break;
      case 7:
        digit[7]++;
        break;
      case 8:
        digit[2] += 3;
        digit[7]++;
        break;
      case 9:
        digit[7]++;
        digit[3] += 2;
        digit[2]++;
        break;
      default:
        break;
    }
  }
  for (i = 2; i <= 9; i++) {
    for (j = 0; j < digit[i]; j++) {
      res[index++] = i;
      size++;
    }
  }
  sort(res, res + size, compare);
  for (i = 0; i < size; i++) {
    printf("%d", res[i]);
  }
  return 0;
}

### 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 digit[12], arr2[20], res[100000];
char arr1[20];
bool compare(int a, int b) {
  if (a > b)
    return true;
  else
    return false;
}
int main() {
  int n, i, j, index = 0, size = 0;
  cin >> n;
  scanf("%s", arr1);
  memset(digit, 0, sizeof(digit));
  memset(res, 0, sizeof(res));
  for (i = 0; i < n; i++) {
    arr2[i] = arr1[i] - '0';
  }
  for (i = 0; i < n; i++) {
    switch (arr2[i] % 10) {
      case 2:
        digit[2]++;
        break;
      case 3:
        digit[3]++;
        break;
      case 4:
        digit[2] += 2;
        digit[3]++;
        break;
      case 5:
        digit[5]++;
        break;
      case 6:
        digit[3]++;
        digit[5]++;
        break;
      case 7:
        digit[7]++;
        break;
      case 8:
        digit[2] += 3;
        digit[7]++;
        break;
      case 9:
        digit[7]++;
        digit[3] += 2;
        digit[2]++;
        break;
      default:
        break;
    }
  }
  for (i = 2; i <= 9; i++) {
    for (j = 0; j < digit[i]; j++) {
      res[index++] = i;
      size++;
    }
  }
  sort(res, res + size, compare);
  for (i = 0; i < size; i++) {
    printf("%d", res[i]);
  }
  return 0;
}

```