#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long t, n;
  cin >> t;
  long long a, co = 0, c = 0, d = 0;
  vector<long long> v;
  cin >> n;
  for (long long i = 0; i < t; i++) {
    c = n % 10;
    if (c == 2) {
      v.push_back(2);
    } else if (c == 3) {
      v.push_back(3);
    } else if (c == 4) {
      v.push_back(3);
      v.push_back(2);
      v.push_back(2);
    } else if (c == 5) {
      v.push_back(5);
    } else if (c == 6) {
      v.push_back(5);
      v.push_back(3);
    } else if (c == 7) {
      v.push_back(7);
    } else if (c == 8) {
      v.push_back(7);
      v.push_back(2);
      v.push_back(2);
      v.push_back(2);
    } else if (c == 9) {
      v.push_back(7);
      v.push_back(3);
      v.push_back(3);
      v.push_back(2);
    }
    n /= 10;
  }
  sort(v.begin(), v.end());
  reverse(v.begin(), v.end());
  for (long long i = 0; i < v.size(); i++) {
    cout << v[i];
  }
  return 0;
}

### 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 main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long t, n;
  cin >> t;
  long long a, co = 0, c = 0, d = 0;
  vector<long long> v;
  cin >> n;
  for (long long i = 0; i < t; i++) {
    c = n % 10;
    if (c == 2) {
      v.push_back(2);
    } else if (c == 3) {
      v.push_back(3);
    } else if (c == 4) {
      v.push_back(3);
      v.push_back(2);
      v.push_back(2);
    } else if (c == 5) {
      v.push_back(5);
    } else if (c == 6) {
      v.push_back(5);
      v.push_back(3);
    } else if (c == 7) {
      v.push_back(7);
    } else if (c == 8) {
      v.push_back(7);
      v.push_back(2);
      v.push_back(2);
      v.push_back(2);
    } else if (c == 9) {
      v.push_back(7);
      v.push_back(3);
      v.push_back(3);
      v.push_back(2);
    }
    n /= 10;
  }
  sort(v.begin(), v.end());
  reverse(v.begin(), v.end());
  for (long long i = 0; i < v.size(); i++) {
    cout << v[i];
  }
  return 0;
}

```