#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long int a, p, q, b = 0, n, k, sum = 0, t = 1, m, x = 0, z, y = 0;
  vector<int> v1, v2, v3, v4;
  string str, s1, s2 = "";
  unordered_map<int, int> mp;
  deque<int> dq;
  unordered_set<int> st;
  vector<pair<int, int>> pr;
  vector<vector<int>> vv;
  cin >> n >> s1;
  for (int i = 0; i < n; i++) {
    if (s1[i] == '0' || s1[i] == '1') {
      continue;
    } else if (s1[i] == '4') {
      s2 += "322";
    } else if (s1[i] == '6') {
      s2 += "53";
    } else if (s1[i] == '8') {
      s2 += "7222";
    } else if (s1[i] == '9') {
      s2 += "7233";
    } else {
      s2 += s1[i];
    }
  }
  sort(s2.begin(), s2.end());
  reverse(s2.begin(), s2.end());
  cout << s2;
  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 main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long int a, p, q, b = 0, n, k, sum = 0, t = 1, m, x = 0, z, y = 0;
  vector<int> v1, v2, v3, v4;
  string str, s1, s2 = "";
  unordered_map<int, int> mp;
  deque<int> dq;
  unordered_set<int> st;
  vector<pair<int, int>> pr;
  vector<vector<int>> vv;
  cin >> n >> s1;
  for (int i = 0; i < n; i++) {
    if (s1[i] == '0' || s1[i] == '1') {
      continue;
    } else if (s1[i] == '4') {
      s2 += "322";
    } else if (s1[i] == '6') {
      s2 += "53";
    } else if (s1[i] == '8') {
      s2 += "7222";
    } else if (s1[i] == '9') {
      s2 += "7233";
    } else {
      s2 += s1[i];
    }
  }
  sort(s2.begin(), s2.end());
  reverse(s2.begin(), s2.end());
  cout << s2;
  return 0;
}

```