#include <bits/stdc++.h>
using namespace std;
long long maxx(long long a, long long b) {
  if (a > b)
    return a;
  else
    return b;
}
int maxxx(int a, int b) {
  if (a > b)
    return a;
  else
    return b;
}
string str;
string ans;
int main() {
  int total, i;
  cin >> total;
  char ch;
  cin >> str;
  for (i = 0; i < total; i++) {
    ch = str[i];
    if (ch == '2') {
      ans.push_back('2');
    } else if (ch == '3') {
      ans.push_back('3');
    } else if (ch == '4') {
      ans.push_back('2');
      ans.push_back('2');
      ans.push_back('3');
    } else if (ch == '5') {
      ans.push_back('5');
    } else if (ch == '6') {
      ans.push_back('3');
      ans.push_back('5');
    } else if (ch == '7') {
      ans.push_back('7');
    } else if (ch == '8') {
      ans.push_back('2');
      ans.push_back('2');
      ans.push_back('2');
      ans.push_back('7');
    } else if (ch == '9') {
      ans.push_back('2');
      ans.push_back('7');
      ans.push_back('3');
      ans.push_back('3');
    }
  }
  sort(ans.begin(), ans.end());
  for (i = ans.size() - 1; i >= 0; i--) cout << ans[i];
  cout << endl;
  return 0;
}

### Prompt

Your task is to create 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;
long long maxx(long long a, long long b) {
  if (a > b)
    return a;
  else
    return b;
}
int maxxx(int a, int b) {
  if (a > b)
    return a;
  else
    return b;
}
string str;
string ans;
int main() {
  int total, i;
  cin >> total;
  char ch;
  cin >> str;
  for (i = 0; i < total; i++) {
    ch = str[i];
    if (ch == '2') {
      ans.push_back('2');
    } else if (ch == '3') {
      ans.push_back('3');
    } else if (ch == '4') {
      ans.push_back('2');
      ans.push_back('2');
      ans.push_back('3');
    } else if (ch == '5') {
      ans.push_back('5');
    } else if (ch == '6') {
      ans.push_back('3');
      ans.push_back('5');
    } else if (ch == '7') {
      ans.push_back('7');
    } else if (ch == '8') {
      ans.push_back('2');
      ans.push_back('2');
      ans.push_back('2');
      ans.push_back('7');
    } else if (ch == '9') {
      ans.push_back('2');
      ans.push_back('7');
      ans.push_back('3');
      ans.push_back('3');
    }
  }
  sort(ans.begin(), ans.end());
  for (i = ans.size() - 1; i >= 0; i--) cout << ans[i];
  cout << endl;
  return 0;
}

```