#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long int n;
  cin >> n;
  vector<long long int> arr[10];
  arr[2].push_back(2);
  arr[3].push_back(3);
  arr[4].push_back(2);
  arr[4].push_back(2);
  arr[4].push_back(3);
  arr[5].push_back(5);
  arr[6].push_back(3);
  arr[6].push_back(5);
  arr[7].push_back(7);
  arr[8].push_back(2);
  arr[8].push_back(2);
  arr[8].push_back(2);
  arr[8].push_back(7);
  arr[9].push_back(2);
  arr[9].push_back(3);
  arr[9].push_back(3);
  arr[9].push_back(7);
  vector<long long int> brr;
  string y;
  cin >> y;
  for (long long int i = 0; i < n; i++) {
    long long int x;
    x = y[i] - '0';
    if (x == 0 || x == 1)
      continue;
    else {
      for (auto it : arr[x]) {
        brr.push_back(it);
      }
    }
  }
  sort(brr.begin(), brr.end(), greater<long long int>());
  for (auto it : brr) cout << it;
  cout << endl;
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}

### Prompt

Your challenge is to write 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;
void solve() {
  long long int n;
  cin >> n;
  vector<long long int> arr[10];
  arr[2].push_back(2);
  arr[3].push_back(3);
  arr[4].push_back(2);
  arr[4].push_back(2);
  arr[4].push_back(3);
  arr[5].push_back(5);
  arr[6].push_back(3);
  arr[6].push_back(5);
  arr[7].push_back(7);
  arr[8].push_back(2);
  arr[8].push_back(2);
  arr[8].push_back(2);
  arr[8].push_back(7);
  arr[9].push_back(2);
  arr[9].push_back(3);
  arr[9].push_back(3);
  arr[9].push_back(7);
  vector<long long int> brr;
  string y;
  cin >> y;
  for (long long int i = 0; i < n; i++) {
    long long int x;
    x = y[i] - '0';
    if (x == 0 || x == 1)
      continue;
    else {
      for (auto it : arr[x]) {
        brr.push_back(it);
      }
    }
  }
  sort(brr.begin(), brr.end(), greater<long long int>());
  for (auto it : brr) cout << it;
  cout << endl;
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}

```