#include <bits/stdc++.h>
using namespace std;
string word, ans = "";
bool cmp(int a, int b) { return a > b; }
void solve(char idx) {
  if (idx == '1')
    return;
  else if (idx == '2' || idx == '3' || idx == '5' || idx == '7')
    ans += idx;
  else if (idx == '4')
    ans += "223";
  else if (idx == '6')
    ans += "35";
  else if (idx == '8')
    ans += "2227";
  else if (idx == '9')
    ans += "2337";
}
int main() {
  int n;
  cin >> n >> word;
  for (int i = 0; i < n; i++) solve(word[i]);
  sort(ans.begin(), ans.end(), cmp);
  cout << ans;
  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;
string word, ans = "";
bool cmp(int a, int b) { return a > b; }
void solve(char idx) {
  if (idx == '1')
    return;
  else if (idx == '2' || idx == '3' || idx == '5' || idx == '7')
    ans += idx;
  else if (idx == '4')
    ans += "223";
  else if (idx == '6')
    ans += "35";
  else if (idx == '8')
    ans += "2227";
  else if (idx == '9')
    ans += "2337";
}
int main() {
  int n;
  cin >> n >> word;
  for (int i = 0; i < n; i++) solve(word[i]);
  sort(ans.begin(), ans.end(), cmp);
  cout << ans;
  return 0;
}

```