#include <bits/stdc++.h>
using namespace std;
long long n, x;
float y;
string s;
vector<long long> v;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n >> s;
  for (long long i = 0; i < n; i++) {
    if ((s[i] - '0') == 1 || (s[i] - '0') == 0)
      continue;
    else if ((s[i] - '0') == 2 || (s[i] - '0' == 3) || (s[i] - '0' == 5) ||
             (s[i] - '0' == 7))
      v.push_back(s[i] - '0');
    else if (s[i] - '0' == 6) {
      v.push_back(3);
      v.push_back(5);
    } else if (s[i] - '0' == 9) {
      v.push_back(3);
      v.push_back(3);
      v.push_back(2);
      v.push_back(7);
    } else {
      x = s[i] - '0';
      y = s[i] - '0';
      while (x == y && x != 1) {
        x /= 2;
        y /= 2;
      }
      if (x == y && x == 1) {
        v.push_back((s[i] - '0') - 1);
        int k = s[i] - '0';
        while (k != 1) {
          k /= 2;
          v.push_back(2);
        }
      } else
        v.push_back(s[i] - '0');
    }
  }
  sort(v.begin(), v.end());
  for (long long i = v.size() - 1; i >= 0; i--) cout << v[i];
  return 0;
}

### Prompt

Please create a solution in cpp 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 n, x;
float y;
string s;
vector<long long> v;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n >> s;
  for (long long i = 0; i < n; i++) {
    if ((s[i] - '0') == 1 || (s[i] - '0') == 0)
      continue;
    else if ((s[i] - '0') == 2 || (s[i] - '0' == 3) || (s[i] - '0' == 5) ||
             (s[i] - '0' == 7))
      v.push_back(s[i] - '0');
    else if (s[i] - '0' == 6) {
      v.push_back(3);
      v.push_back(5);
    } else if (s[i] - '0' == 9) {
      v.push_back(3);
      v.push_back(3);
      v.push_back(2);
      v.push_back(7);
    } else {
      x = s[i] - '0';
      y = s[i] - '0';
      while (x == y && x != 1) {
        x /= 2;
        y /= 2;
      }
      if (x == y && x == 1) {
        v.push_back((s[i] - '0') - 1);
        int k = s[i] - '0';
        while (k != 1) {
          k /= 2;
          v.push_back(2);
        }
      } else
        v.push_back(s[i] - '0');
    }
  }
  sort(v.begin(), v.end());
  for (long long i = v.size() - 1; i >= 0; i--) cout << v[i];
  return 0;
}

```