#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> v[10] = {{0}, {0},    {2}, {3},          {3, 2, 2},
                     {5}, {5, 3}, {7}, {7, 2, 2, 2}, {7, 3, 3, 2}},
            ans;
string str;
int main() {
  cin >> n >> str;
  for (int i = 0; i < n; i++) {
    for (auto x : v[str[i] - '0']) {
      ans.push_back(x);
    }
  }
  sort(ans.begin(), ans.end(), greater<int>());
  for (auto x : ans) {
    if (x == 0) break;
    cout << x;
  }
  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;
int n;
vector<int> v[10] = {{0}, {0},    {2}, {3},          {3, 2, 2},
                     {5}, {5, 3}, {7}, {7, 2, 2, 2}, {7, 3, 3, 2}},
            ans;
string str;
int main() {
  cin >> n >> str;
  for (int i = 0; i < n; i++) {
    for (auto x : v[str[i] - '0']) {
      ans.push_back(x);
    }
  }
  sort(ans.begin(), ans.end(), greater<int>());
  for (auto x : ans) {
    if (x == 0) break;
    cout << x;
  }
  return 0;
}

```