#include <bits/stdc++.h>
using namespace std;
vector<int> v;
void fun(int n) {
  if (n == 0) return;
  switch (n) {
    case 1:
      break;
    case 2:
      v.push_back(2);
      break;
    case 3:
      v.push_back(3);
      break;
    case 4:
      v.push_back(2);
      v.push_back(2);
      v.push_back(3);
      break;
    case 5:
      v.push_back(5);
      break;
    case 6:
      v.push_back(5);
      v.push_back(3);
      break;
    case 7:
      v.push_back(7);
      break;
    case 8:
      v.push_back(7);
      v.push_back(2);
      v.push_back(2);
      v.push_back(2);
      break;
    case 9:
      v.push_back(7);
      v.push_back(3);
      v.push_back(3);
      v.push_back(2);
      break;
    default:
      break;
  }
}
int main() {
  int t, i, n, num;
  string str;
  v.clear();
  cin >> n;
  cin >> str;
  for (i = 0; i < n; i++) {
    num = str[i] - '0';
    fun(num);
  }
  sort(v.begin(), v.end());
  for (i = v.size() - 1; i >= 0; i--) cout << v[i];
  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>
using namespace std;
vector<int> v;
void fun(int n) {
  if (n == 0) return;
  switch (n) {
    case 1:
      break;
    case 2:
      v.push_back(2);
      break;
    case 3:
      v.push_back(3);
      break;
    case 4:
      v.push_back(2);
      v.push_back(2);
      v.push_back(3);
      break;
    case 5:
      v.push_back(5);
      break;
    case 6:
      v.push_back(5);
      v.push_back(3);
      break;
    case 7:
      v.push_back(7);
      break;
    case 8:
      v.push_back(7);
      v.push_back(2);
      v.push_back(2);
      v.push_back(2);
      break;
    case 9:
      v.push_back(7);
      v.push_back(3);
      v.push_back(3);
      v.push_back(2);
      break;
    default:
      break;
  }
}
int main() {
  int t, i, n, num;
  string str;
  v.clear();
  cin >> n;
  cin >> str;
  for (i = 0; i < n; i++) {
    num = str[i] - '0';
    fun(num);
  }
  sort(v.begin(), v.end());
  for (i = v.size() - 1; i >= 0; i--) cout << v[i];
  return 0;
}

```