#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int t = 1;
  while (t--) {
    long long int n, sum = 0, ans = 0, ct = 0, m, l, r, k, d;
    cin >> n;
    string s;
    cin >> s;
    string a = "";
    for (long long int i = 0; i < n; i++) {
      if (s[i] == '1' || s[i] == '0') continue;
      if (s[i] == '2' || s[i] == '3') {
        a += s[i];
        continue;
      }
      if (s[i] == '4') a += "223";
      if (s[i] == '9') a += "3327";
      if (s[i] == '7' || s[i] == '5') a += s[i];
      if (s[i] == '6') a += "35";
      if (s[i] == '8') a += "2227";
    }
    sort(a.begin(), a.end());
    reverse(a.begin(), a.end());
    cout << a << '\n';
  }
  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() {
  long long int t = 1;
  while (t--) {
    long long int n, sum = 0, ans = 0, ct = 0, m, l, r, k, d;
    cin >> n;
    string s;
    cin >> s;
    string a = "";
    for (long long int i = 0; i < n; i++) {
      if (s[i] == '1' || s[i] == '0') continue;
      if (s[i] == '2' || s[i] == '3') {
        a += s[i];
        continue;
      }
      if (s[i] == '4') a += "223";
      if (s[i] == '9') a += "3327";
      if (s[i] == '7' || s[i] == '5') a += s[i];
      if (s[i] == '6') a += "35";
      if (s[i] == '8') a += "2227";
    }
    sort(a.begin(), a.end());
    reverse(a.begin(), a.end());
    cout << a << '\n';
  }
  return 0;
}

```