#include <bits/stdc++.h>
using namespace std;
const long long int mod = 1e9 + 7;
long long int n, m, k, l;
void solve() {
  long long int n;
  cin >> n;
  string s;
  cin >> s;
  string s1 = "";
  for (__typeof(n) i = (0) - ((0) > (n)); i != (n) - ((0) > (n));
       i += 1 - 2 * ((0) > (n))) {
    if (s[i] == '0' or s[i] == '1')
      continue;
    else if (s[i] == '4') {
      s1 += '2';
      s1 += '2';
      s1 += '3';
    } else if (s[i] == '6') {
      s1 += '3';
      s1 += '5';
    } else if (s[i] == '8') {
      s1 += '2';
      s1 += '2';
      s1 += '2';
      s1 += '7';
    } else if (s[i] == '9') {
      s1 += '3';
      s1 += '3';
      s1 += '2';
      s1 += '7';
    } else
      s1 += s[i];
  }
  sort(s1.begin(), s1.end(), greater<char>());
  cout << s1 << "\n";
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long int t;
  t = 1;
  while (t--) {
    solve();
  }
  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;
const long long int mod = 1e9 + 7;
long long int n, m, k, l;
void solve() {
  long long int n;
  cin >> n;
  string s;
  cin >> s;
  string s1 = "";
  for (__typeof(n) i = (0) - ((0) > (n)); i != (n) - ((0) > (n));
       i += 1 - 2 * ((0) > (n))) {
    if (s[i] == '0' or s[i] == '1')
      continue;
    else if (s[i] == '4') {
      s1 += '2';
      s1 += '2';
      s1 += '3';
    } else if (s[i] == '6') {
      s1 += '3';
      s1 += '5';
    } else if (s[i] == '8') {
      s1 += '2';
      s1 += '2';
      s1 += '2';
      s1 += '7';
    } else if (s[i] == '9') {
      s1 += '3';
      s1 += '3';
      s1 += '2';
      s1 += '7';
    } else
      s1 += s[i];
  }
  sort(s1.begin(), s1.end(), greater<char>());
  cout << s1 << "\n";
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long int t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}

```