#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9 + 1;
inline long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
void FileIO() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
}
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  string res = "";
  for (int i = 0; i < n; i++) {
    int r = s[i];
    if (r == '2' || r == '3' || r == '5' || r == '7')
      res += string(1, r);
    else if (r == '4') {
      res += "223";
    } else if (r == '6') {
      res += "35";
    } else if (r == '8') {
      res += "2227";
    } else if (r == '9')
      res += "3327";
  }
  sort(res.begin(), res.end(), greater<char>());
  cout << res;
}

### 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;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9 + 1;
inline long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
void FileIO() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
}
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  string res = "";
  for (int i = 0; i < n; i++) {
    int r = s[i];
    if (r == '2' || r == '3' || r == '5' || r == '7')
      res += string(1, r);
    else if (r == '4') {
      res += "223";
    } else if (r == '6') {
      res += "35";
    } else if (r == '8') {
      res += "2227";
    } else if (r == '9')
      res += "3327";
  }
  sort(res.begin(), res.end(), greater<char>());
  cout << res;
}

```