#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, cnt[10] = {0}, result[10] = {0};
  scanf("%d", &n);
  char c;
  for (i = 0; i <= n; i++) {
    scanf("%c", &c);
    cnt[c - '0']++;
  }
  for (i = 0; i <= 9; i++) {
    if (i == 9) {
      result[3] += cnt[i] * 2;
      result[2] += cnt[i] * 1;
      result[7] += cnt[i] * 1;
    } else if (i == 8) {
      result[7] += cnt[i] * 1;
      result[2] += cnt[i] * 3;
    } else if (i == 7) {
      result[7] += cnt[i] * 1;
    } else if (i == 6) {
      result[5] += cnt[i] * 1;
      result[3] += cnt[i] * 1;
    } else if (i == 5) {
      result[5] += cnt[i] * 1;
    } else if (i == 4) {
      result[2] += cnt[i] * 2;
      result[3] += cnt[i] * 1;
    } else if (i == 3) {
      result[3] += cnt[i] * 1;
    } else if (i == 2) {
      result[2] += cnt[i] * 1;
    }
  }
  for (i = 9; i > 1; i--) {
    while (result[i] > 0) {
      printf("%d", i);
      result[i]--;
    }
  }
  printf("\n");
  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 main() {
  int n, i, cnt[10] = {0}, result[10] = {0};
  scanf("%d", &n);
  char c;
  for (i = 0; i <= n; i++) {
    scanf("%c", &c);
    cnt[c - '0']++;
  }
  for (i = 0; i <= 9; i++) {
    if (i == 9) {
      result[3] += cnt[i] * 2;
      result[2] += cnt[i] * 1;
      result[7] += cnt[i] * 1;
    } else if (i == 8) {
      result[7] += cnt[i] * 1;
      result[2] += cnt[i] * 3;
    } else if (i == 7) {
      result[7] += cnt[i] * 1;
    } else if (i == 6) {
      result[5] += cnt[i] * 1;
      result[3] += cnt[i] * 1;
    } else if (i == 5) {
      result[5] += cnt[i] * 1;
    } else if (i == 4) {
      result[2] += cnt[i] * 2;
      result[3] += cnt[i] * 1;
    } else if (i == 3) {
      result[3] += cnt[i] * 1;
    } else if (i == 2) {
      result[2] += cnt[i] * 1;
    }
  }
  for (i = 9; i > 1; i--) {
    while (result[i] > 0) {
      printf("%d", i);
      result[i]--;
    }
  }
  printf("\n");
  return 0;
}

```