#include <bits/stdc++.h>
using namespace std;
const long long N = 100;
long long n, x, i, j, y = 1, t;
vector<long long> ans;
void work(long long x) {
  if (x <= 1) return;
  if (x == 8) {
    ans.push_back(2);
    ans.push_back(2);
    ans.push_back(2);
    ans.push_back(7);
  } else if (x == 4) {
    ans.push_back(2);
    ans.push_back(2);
    ans.push_back(3);
  } else if (x == 6) {
    ans.push_back(3);
    ans.push_back(5);
  } else if (x == 9) {
    ans.push_back(3);
    ans.push_back(3);
    ans.push_back(2);
    ans.push_back(7);
  } else
    ans.push_back(x);
}
int main() {
  cin >> n >> x;
  t = x;
  while (t) {
    work(t % 10);
    t /= 10;
  }
  sort(ans.rbegin(), ans.rend());
  for (i = 0; i < ans.size(); i++) cout << ans[i];
  cout << endl;
  return 0;
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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;
const long long N = 100;
long long n, x, i, j, y = 1, t;
vector<long long> ans;
void work(long long x) {
  if (x <= 1) return;
  if (x == 8) {
    ans.push_back(2);
    ans.push_back(2);
    ans.push_back(2);
    ans.push_back(7);
  } else if (x == 4) {
    ans.push_back(2);
    ans.push_back(2);
    ans.push_back(3);
  } else if (x == 6) {
    ans.push_back(3);
    ans.push_back(5);
  } else if (x == 9) {
    ans.push_back(3);
    ans.push_back(3);
    ans.push_back(2);
    ans.push_back(7);
  } else
    ans.push_back(x);
}
int main() {
  cin >> n >> x;
  t = x;
  while (t) {
    work(t % 10);
    t /= 10;
  }
  sort(ans.rbegin(), ans.rend());
  for (i = 0; i < ans.size(); i++) cout << ans[i];
  cout << endl;
  return 0;
}

```