#include <bits/stdc++.h>
using namespace std;
template <class T>
void print_array(T a[], int size) {
  for (int i = 0; i < size; i++) cout << a[i] << " ";
  cout << endl;
}
template <class T>
void print_array_v(T &a) {
  int size = a.size();
  for (int i = 0; i < size; i++) cout << a[i] << " ";
  cout << endl;
}
int main() {
  string vals[10] = {"0", "1", "2", "3", "322", "5", "53", "7", "7222", "7332"};
  int n;
  scanf("%d", &n);
  char second[20];
  scanf("%s", second);
  string ans;
  for (int i = 0; i < n; i++)
    if (second[i] > '1') ans += vals[second[i] - '0'];
  sort(ans.begin(), ans.end(), greater<char>());
  cout << ans << 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;
template <class T>
void print_array(T a[], int size) {
  for (int i = 0; i < size; i++) cout << a[i] << " ";
  cout << endl;
}
template <class T>
void print_array_v(T &a) {
  int size = a.size();
  for (int i = 0; i < size; i++) cout << a[i] << " ";
  cout << endl;
}
int main() {
  string vals[10] = {"0", "1", "2", "3", "322", "5", "53", "7", "7222", "7332"};
  int n;
  scanf("%d", &n);
  char second[20];
  scanf("%s", second);
  string ans;
  for (int i = 0; i < n; i++)
    if (second[i] > '1') ans += vals[second[i] - '0'];
  sort(ans.begin(), ans.end(), greater<char>());
  cout << ans << endl;
  return 0;
}

```