#include <bits/stdc++.h>
using ll = long long;
ll constexpr INF = 1e18;
int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(NULL);
  int n;
  std::cin >> n;
  std::string s;
  std::cin >> s;
  std::map<char, std::string> map;
  map.insert(std::make_pair('1', ""));
  map.insert(std::make_pair('2', "2"));
  map.insert(std::make_pair('3', "3"));
  map.insert(std::make_pair('4', "322"));
  map.insert(std::make_pair('5', "5"));
  map.insert(std::make_pair('6', "53"));
  map.insert(std::make_pair('7', "7"));
  map.insert(std::make_pair('8', "7222"));
  map.insert(std::make_pair('9', "7332"));
  std::string res;
  for (int i = 0; i < s.size(); ++i) {
    res = res + map[s[i]];
  }
  std::sort(res.begin(), res.end());
  std::reverse(res.begin(), res.end());
  std::cout << res << '\n';
}

### Prompt

Please formulate 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 ll = long long;
ll constexpr INF = 1e18;
int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(NULL);
  int n;
  std::cin >> n;
  std::string s;
  std::cin >> s;
  std::map<char, std::string> map;
  map.insert(std::make_pair('1', ""));
  map.insert(std::make_pair('2', "2"));
  map.insert(std::make_pair('3', "3"));
  map.insert(std::make_pair('4', "322"));
  map.insert(std::make_pair('5', "5"));
  map.insert(std::make_pair('6', "53"));
  map.insert(std::make_pair('7', "7"));
  map.insert(std::make_pair('8', "7222"));
  map.insert(std::make_pair('9', "7332"));
  std::string res;
  for (int i = 0; i < s.size(); ++i) {
    res = res + map[s[i]];
  }
  std::sort(res.begin(), res.end());
  std::reverse(res.begin(), res.end());
  std::cout << res << '\n';
}

```