#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
int main() {
  std::ios::sync_with_stdio(false);
  int n;
  cin >> n;
  long long num;
  cin >> num;
  long long fac[10];
  fac[0] = 1;
  for (int i = 1; i < 10; i++) fac[i] = fac[i - 1] * i;
  long long res = 1, num1 = num;
  vector<long long> vec;
  for (int i = 0; i < n; i++) {
    long long a = num1 % 10;
    if (a == 4) {
      vec.push_back(3);
      vec.push_back(2);
      vec.push_back(2);
    }
    if (a == 6) {
      vec.push_back(5);
      vec.push_back(3);
    }
    if (a == 8) {
      vec.push_back(7);
      vec.push_back(2);
      vec.push_back(2);
      vec.push_back(2);
    }
    if (a == 9) {
      vec.push_back(7);
      vec.push_back(3);
      vec.push_back(3);
      vec.push_back(2);
    }
    if (a == 2 || a == 3 || a == 5 || a == 7) {
      vec.push_back(a);
    }
    num1 /= 10;
  }
  sort(vec.begin(), vec.end());
  for (int i = vec.size() - 1; i > -1; i--) cout << vec[i];
  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;
long long mod = 1000000007;
int main() {
  std::ios::sync_with_stdio(false);
  int n;
  cin >> n;
  long long num;
  cin >> num;
  long long fac[10];
  fac[0] = 1;
  for (int i = 1; i < 10; i++) fac[i] = fac[i - 1] * i;
  long long res = 1, num1 = num;
  vector<long long> vec;
  for (int i = 0; i < n; i++) {
    long long a = num1 % 10;
    if (a == 4) {
      vec.push_back(3);
      vec.push_back(2);
      vec.push_back(2);
    }
    if (a == 6) {
      vec.push_back(5);
      vec.push_back(3);
    }
    if (a == 8) {
      vec.push_back(7);
      vec.push_back(2);
      vec.push_back(2);
      vec.push_back(2);
    }
    if (a == 9) {
      vec.push_back(7);
      vec.push_back(3);
      vec.push_back(3);
      vec.push_back(2);
    }
    if (a == 2 || a == 3 || a == 5 || a == 7) {
      vec.push_back(a);
    }
    num1 /= 10;
  }
  sort(vec.begin(), vec.end());
  for (int i = vec.size() - 1; i > -1; i--) cout << vec[i];
  return 0;
}

```