#include <bits/stdc++.h>
using namespace std;
int binarySearch(int arr[], int l, int r, int x) {
  if (r >= l) {
    int mid = l + (r - l) / 2;
    if (arr[mid] == x) return mid;
    if (arr[mid] > x) return binarySearch(arr, l, mid - 1, x);
    return binarySearch(arr, mid + 1, r, x);
  }
  return l;
}
void swap(long long int *p1, long long int *p2) {
  long long int temp = *p1;
  *p1 = *p2;
  *p2 = temp;
}
bool ispalindrome(string s) {
  long long int n = s.length();
  for (long long int i = 0; i < n; i++) {
    if (s[i] != s[n - 1 - i]) return false;
  }
  return true;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n;
  vector<long long int> vect;
  cin >> n;
  string s;
  cin >> s;
  for (long long int i = 0; i < n; i++) {
    long long int x = s[i] - '0';
    if (x == 4) {
      vect.push_back(2);
      vect.push_back(2);
      vect.push_back(3);
    } else if (x == 6) {
      vect.push_back(5);
      vect.push_back(3);
    } else if (x == 0)
      continue;
    else if (x == 1)
      continue;
    else if (x == 8) {
      vect.push_back(2);
      vect.push_back(2);
      vect.push_back(2);
      vect.push_back(7);
    } else if (x == 9) {
      vect.push_back(3);
      vect.push_back(3);
      vect.push_back(2);
      vect.push_back(7);
    } else
      vect.push_back(x);
  }
  sort(vect.begin(), vect.end(), greater<long long int>());
  for (long long int i = 0; i < vect.size(); i++) cout << vect[i];
}

### Prompt

In cpp, your task is to solve 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 binarySearch(int arr[], int l, int r, int x) {
  if (r >= l) {
    int mid = l + (r - l) / 2;
    if (arr[mid] == x) return mid;
    if (arr[mid] > x) return binarySearch(arr, l, mid - 1, x);
    return binarySearch(arr, mid + 1, r, x);
  }
  return l;
}
void swap(long long int *p1, long long int *p2) {
  long long int temp = *p1;
  *p1 = *p2;
  *p2 = temp;
}
bool ispalindrome(string s) {
  long long int n = s.length();
  for (long long int i = 0; i < n; i++) {
    if (s[i] != s[n - 1 - i]) return false;
  }
  return true;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n;
  vector<long long int> vect;
  cin >> n;
  string s;
  cin >> s;
  for (long long int i = 0; i < n; i++) {
    long long int x = s[i] - '0';
    if (x == 4) {
      vect.push_back(2);
      vect.push_back(2);
      vect.push_back(3);
    } else if (x == 6) {
      vect.push_back(5);
      vect.push_back(3);
    } else if (x == 0)
      continue;
    else if (x == 1)
      continue;
    else if (x == 8) {
      vect.push_back(2);
      vect.push_back(2);
      vect.push_back(2);
      vect.push_back(7);
    } else if (x == 9) {
      vect.push_back(3);
      vect.push_back(3);
      vect.push_back(2);
      vect.push_back(7);
    } else
      vect.push_back(x);
  }
  sort(vect.begin(), vect.end(), greater<long long int>());
  for (long long int i = 0; i < vect.size(); i++) cout << vect[i];
}

```