#include <bits/stdc++.h>
using namespace std;
const int INF = int(1e9);
const long long INFll = 1ll * INF * INF;
const int MOD = 1000000007;
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  int n;
  cin >> n;
  vector<int> k(10);
  for (int i = 0; i < n; ++i) {
    char x;
    cin >> x;
    int a = x - '0';
    for (int j = 2; j <= a; ++j) {
      if (j == 4)
        k[2] += 2;
      else if (j == 6)
        k[2]++, k[3]++;
      else if (j == 8)
        k[2] += 3;
      else if (j == 9)
        k[3] += 2;
      else
        k[j]++;
    }
  }
  int cur = 0;
  for (int j = 9; j >= 0; --j) {
    for (int i = 0; i < k[j]; ++i) cout << j;
    for (int i = 0; i < k[j]; ++i)
      for (int z = 2; z < j; ++z) {
        if (z == 4)
          k[2] -= 2;
        else if (z == 6)
          k[2]--, k[3]--;
        else if (z == 8)
          k[2] -= 3;
        else if (z == 9)
          k[3] -= 2;
        else
          k[z]--;
      }
  }
  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 INF = int(1e9);
const long long INFll = 1ll * INF * INF;
const int MOD = 1000000007;
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  int n;
  cin >> n;
  vector<int> k(10);
  for (int i = 0; i < n; ++i) {
    char x;
    cin >> x;
    int a = x - '0';
    for (int j = 2; j <= a; ++j) {
      if (j == 4)
        k[2] += 2;
      else if (j == 6)
        k[2]++, k[3]++;
      else if (j == 8)
        k[2] += 3;
      else if (j == 9)
        k[3] += 2;
      else
        k[j]++;
    }
  }
  int cur = 0;
  for (int j = 9; j >= 0; --j) {
    for (int i = 0; i < k[j]; ++i) cout << j;
    for (int i = 0; i < k[j]; ++i)
      for (int z = 2; z < j; ++z) {
        if (z == 4)
          k[2] -= 2;
        else if (z == 6)
          k[2]--, k[3]--;
        else if (z == 8)
          k[2] -= 3;
        else if (z == 9)
          k[3] -= 2;
        else
          k[z]--;
      }
  }
  return 0;
}

```