#include <bits/stdc++.h>
using namespace std;
void t_i() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
long long int gcd(long long int a, long long int b) {
  if (a < b) swap(a, b);
  if (b == 0) return a;
  return gcd(b, a % b);
}
typedef struct {
  int a, b;
} value;
bool compare(value x, value y) {
  if (x.a == y.a) return x.b < y.b;
  return x.a < y.a;
}
int main() {
  t_i();
  int n;
  cin >> n;
  string s;
  cin >> s;
  string ans;
  for (int i = 0; i < n; i++) {
    if (s[i] == '1' || s[i] == '0') continue;
    if (s[i] == '4' || s[i] == '6' || s[i] == '8' || s[i] == '9') {
      if (s[i] == '4') {
        ans += "223";
      }
      if (s[i] == '6') {
        ans += "35";
      }
      if (s[i] == '8') {
        ans += "2227";
      }
      if (s[i] == '9') {
        ans += "2337";
      }
    } else {
      ans += s[i];
    }
  }
  sort(ans.begin(), ans.end(), greater<char>());
  cout << ans << endl;
  return 0;
}

### Prompt

Generate 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;
void t_i() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
long long int gcd(long long int a, long long int b) {
  if (a < b) swap(a, b);
  if (b == 0) return a;
  return gcd(b, a % b);
}
typedef struct {
  int a, b;
} value;
bool compare(value x, value y) {
  if (x.a == y.a) return x.b < y.b;
  return x.a < y.a;
}
int main() {
  t_i();
  int n;
  cin >> n;
  string s;
  cin >> s;
  string ans;
  for (int i = 0; i < n; i++) {
    if (s[i] == '1' || s[i] == '0') continue;
    if (s[i] == '4' || s[i] == '6' || s[i] == '8' || s[i] == '9') {
      if (s[i] == '4') {
        ans += "223";
      }
      if (s[i] == '6') {
        ans += "35";
      }
      if (s[i] == '8') {
        ans += "2227";
      }
      if (s[i] == '9') {
        ans += "2337";
      }
    } else {
      ans += s[i];
    }
  }
  sort(ans.begin(), ans.end(), greater<char>());
  cout << ans << endl;
  return 0;
}

```