#include <bits/stdc++.h>
using namespace std;
string targetNumber(string s) {
  string ans;
  for (int i = 0; i < s.length(); i++)
    if (s[i] != '0' && s[i] != '1') ans += s[i];
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  cin >> n;
  string str;
  cin >> str;
  string s = targetNumber(str);
  string ans;
  unordered_map<char, string> um;
  um['4'] = "223";
  um['6'] = "35";
  um['8'] = "2227";
  for (int i = 2; i <= 9; i++) {
    if (i == 4)
      um['4'] = "223";
    else if (i == 6)
      um['6'] = "35";
    else if (i == 8)
      um['8'] = "2227";
    else if (i == 9)
      um['9'] = "3327";
    else
      um[i + '0'] += (i + '0');
  }
  for (int i = 0; i < s.length(); i++) ans += um[s[i]];
  sort(ans.begin(), ans.end(), greater<char>());
  cout << ans;
  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;
string targetNumber(string s) {
  string ans;
  for (int i = 0; i < s.length(); i++)
    if (s[i] != '0' && s[i] != '1') ans += s[i];
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  cin >> n;
  string str;
  cin >> str;
  string s = targetNumber(str);
  string ans;
  unordered_map<char, string> um;
  um['4'] = "223";
  um['6'] = "35";
  um['8'] = "2227";
  for (int i = 2; i <= 9; i++) {
    if (i == 4)
      um['4'] = "223";
    else if (i == 6)
      um['6'] = "35";
    else if (i == 8)
      um['8'] = "2227";
    else if (i == 9)
      um['9'] = "3327";
    else
      um[i + '0'] += (i + '0');
  }
  for (int i = 0; i < s.length(); i++) ans += um[s[i]];
  sort(ans.begin(), ans.end(), greater<char>());
  cout << ans;
  return 0;
}

```