#include <bits/stdc++.h>
using namespace std;
int n;
string s;
int char_decode(char ch) {
  if (ch == 'R')
    return 0;
  else if (ch == 'G')
    return 1;
  else
    return 2;
}
char char_encode(int i) {
  if (i == 0)
    return 'R';
  else if (i == 1)
    return 'G';
  else
    return 'B';
}
int main() {
  int n;
  string s;
  cin >> n >> s;
  string ans = "";
  for (int i = 0; i < n; ++i) {
    if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3' ||
        s[i] == '5' || s[i] == '7') {
      if (s[i] == '0' || s[i] == '1') continue;
      ans += s[i];
    } else if (s[i] == '4') {
      ans += '3';
      ans += "22";
    } else if (s[i] == '6') {
      ans += '5';
      ans += '3';
    } else if (s[i] == '8') {
      ans += '7';
      ans += "222";
    } else {
      ans += '7';
      ans += '2';
      ans += "33";
    }
  }
  sort(ans.begin(), ans.end());
  reverse(ans.begin(), ans.end());
  cout << ans << endl;
  return 0;
}

### 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 namespace std;
int n;
string s;
int char_decode(char ch) {
  if (ch == 'R')
    return 0;
  else if (ch == 'G')
    return 1;
  else
    return 2;
}
char char_encode(int i) {
  if (i == 0)
    return 'R';
  else if (i == 1)
    return 'G';
  else
    return 'B';
}
int main() {
  int n;
  string s;
  cin >> n >> s;
  string ans = "";
  for (int i = 0; i < n; ++i) {
    if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3' ||
        s[i] == '5' || s[i] == '7') {
      if (s[i] == '0' || s[i] == '1') continue;
      ans += s[i];
    } else if (s[i] == '4') {
      ans += '3';
      ans += "22";
    } else if (s[i] == '6') {
      ans += '5';
      ans += '3';
    } else if (s[i] == '8') {
      ans += '7';
      ans += "222";
    } else {
      ans += '7';
      ans += '2';
      ans += "33";
    }
  }
  sort(ans.begin(), ans.end());
  reverse(ans.begin(), ans.end());
  cout << ans << endl;
  return 0;
}

```