#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  int a[n], i = 0, ct2 = 0, ct3 = 0;
  for (int i = 0; i < n; i++) {
    a[i] = (int)s[i] - 48;
  }
  sort(a, a + n, greater<int>());
  for (int i = 0; i < n; i++) {
    if (a[i] == 1 || a[i] == 0)
      continue;
    else if (a[i] == 2) {
      ct2++;
    } else if (a[i] == 3) {
      ct3++;
    } else if (a[i] == 4) {
      ct2 += 2;
      ct3++;
    } else if (a[i] == 5) {
      cout << a[i];
    } else if (a[i] == 6) {
      cout << a[i] - 1;
      ct3++;
    } else if (a[i] == 7) {
      cout << a[i];
    } else if (a[i] == 8) {
      cout << a[i] - 1;
      ct2 += 3;
    } else if (a[i] == 9) {
      cout << 7;
      ct2++;
      ct3 += 2;
    }
  }
  while (ct3 > 0) {
    cout << 3;
    ct3--;
  }
  while (ct2 > 0) {
    cout << 2;
    ct2--;
  }
  return 0;
}

### Prompt

Create a solution in cpp for 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 main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  int a[n], i = 0, ct2 = 0, ct3 = 0;
  for (int i = 0; i < n; i++) {
    a[i] = (int)s[i] - 48;
  }
  sort(a, a + n, greater<int>());
  for (int i = 0; i < n; i++) {
    if (a[i] == 1 || a[i] == 0)
      continue;
    else if (a[i] == 2) {
      ct2++;
    } else if (a[i] == 3) {
      ct3++;
    } else if (a[i] == 4) {
      ct2 += 2;
      ct3++;
    } else if (a[i] == 5) {
      cout << a[i];
    } else if (a[i] == 6) {
      cout << a[i] - 1;
      ct3++;
    } else if (a[i] == 7) {
      cout << a[i];
    } else if (a[i] == 8) {
      cout << a[i] - 1;
      ct2 += 3;
    } else if (a[i] == 9) {
      cout << 7;
      ct2++;
      ct3 += 2;
    }
  }
  while (ct3 > 0) {
    cout << 3;
    ct3--;
  }
  while (ct2 > 0) {
    cout << 2;
    ct2--;
  }
  return 0;
}

```