#include <bits/stdc++.h>
using namespace std;
const int SigmaSize = 3;
const int MaxA = 1e5 + 7;
const int MaxB = 2e5 + 7;
const int MaxC = 6e5 + 7;
int n;
char str[233];
int op[MaxA], len;
int main() {
  while (~scanf("%d", &n)) {
    scanf("%s", str);
    len = 0;
    for (int i = 0; i < n; i++) {
      int num = str[i] - '0';
      if (num == 2 || num == 3 || num == 5 || num == 7)
        op[len++] = num;
      else if (num == 4) {
        op[len++] = 2;
        op[len++] = 2;
        op[len++] = 3;
      } else if (num == 6) {
        op[len++] = 3;
        op[len++] = 5;
      } else if (num == 8) {
        op[len++] = 2;
        op[len++] = 2;
        op[len++] = 2;
        op[len++] = 7;
      } else if (num == 9) {
        op[len++] = 2;
        op[len++] = 3;
        op[len++] = 3;
        op[len++] = 7;
      }
    }
    sort(op, op + len);
    for (int i = len - 1; i >= 0; i--) {
      printf("%d", op[i]);
    }
    printf("\n");
  }
  return 0;
}

### 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;
const int SigmaSize = 3;
const int MaxA = 1e5 + 7;
const int MaxB = 2e5 + 7;
const int MaxC = 6e5 + 7;
int n;
char str[233];
int op[MaxA], len;
int main() {
  while (~scanf("%d", &n)) {
    scanf("%s", str);
    len = 0;
    for (int i = 0; i < n; i++) {
      int num = str[i] - '0';
      if (num == 2 || num == 3 || num == 5 || num == 7)
        op[len++] = num;
      else if (num == 4) {
        op[len++] = 2;
        op[len++] = 2;
        op[len++] = 3;
      } else if (num == 6) {
        op[len++] = 3;
        op[len++] = 5;
      } else if (num == 8) {
        op[len++] = 2;
        op[len++] = 2;
        op[len++] = 2;
        op[len++] = 7;
      } else if (num == 9) {
        op[len++] = 2;
        op[len++] = 3;
        op[len++] = 3;
        op[len++] = 7;
      }
    }
    sort(op, op + len);
    for (int i = len - 1; i >= 0; i--) {
      printf("%d", op[i]);
    }
    printf("\n");
  }
  return 0;
}

```