#include <bits/stdc++.h>
char sr[20];
int answer[1000];
int main() {
  int N, n = 0;
  scanf("%d", &N);
  scanf("%s", sr);
  for (int i = 0; sr[i]; i++) {
    if (sr[i] < '2') continue;
    if (sr[i] == '3' || sr[i] == '5' || sr[i] == '7' || sr[i] == '2')
      answer[n++] = sr[i] - '0';
    if (sr[i] == '4') {
      answer[n++] = 3;
      answer[n++] = 2;
      answer[n++] = 2;
    }
    if (sr[i] == '6') {
      answer[n++] = 3;
      answer[n++] = 5;
    }
    if (sr[i] == '8') {
      answer[n++] = 2;
      answer[n++] = 2;
      answer[n++] = 2;
      answer[n++] = 7;
    }
    if (sr[i] == '9') {
      answer[n++] = 7;
      answer[n++] = 2;
      answer[n++] = 3;
      answer[n++] = 3;
    }
  }
  std::sort(answer, answer + n);
  for (int i = n - 1; ~i; i--) printf("%d", answer[i]);
  puts("");
  return 0;
}

### Prompt

Please create a solution in cpp 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>
char sr[20];
int answer[1000];
int main() {
  int N, n = 0;
  scanf("%d", &N);
  scanf("%s", sr);
  for (int i = 0; sr[i]; i++) {
    if (sr[i] < '2') continue;
    if (sr[i] == '3' || sr[i] == '5' || sr[i] == '7' || sr[i] == '2')
      answer[n++] = sr[i] - '0';
    if (sr[i] == '4') {
      answer[n++] = 3;
      answer[n++] = 2;
      answer[n++] = 2;
    }
    if (sr[i] == '6') {
      answer[n++] = 3;
      answer[n++] = 5;
    }
    if (sr[i] == '8') {
      answer[n++] = 2;
      answer[n++] = 2;
      answer[n++] = 2;
      answer[n++] = 7;
    }
    if (sr[i] == '9') {
      answer[n++] = 7;
      answer[n++] = 2;
      answer[n++] = 3;
      answer[n++] = 3;
    }
  }
  std::sort(answer, answer + n);
  for (int i = n - 1; ~i; i--) printf("%d", answer[i]);
  puts("");
  return 0;
}

```