#include <bits/stdc++.h>
using namespace std;
long n, m;
char a[1001];
long f[101];
string t[10];
int main() {
  cin >> n;
  for (int k = 1; k <= n; ++k) cin >> a[k];
  f[0] = 1;
  for (int k = 1; k <= 9; ++k) f[k] = f[k - 1] * 2;
  long long d = 1;
  t[9] = "7332";
  t[8] = "7222";
  t[7] = "7";
  t[6] = "53";
  t[5] = "5";
  t[4] = "322";
  t[3] = "3";
  t[2] = "2";
  string s = "";
  for (int k = 1; k <= n; ++k) s = s + t[a[k] - '0'];
  sort(s.begin(), s.end());
  reverse(s.begin(), s.end());
  cout << s;
  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 n, m;
char a[1001];
long f[101];
string t[10];
int main() {
  cin >> n;
  for (int k = 1; k <= n; ++k) cin >> a[k];
  f[0] = 1;
  for (int k = 1; k <= 9; ++k) f[k] = f[k - 1] * 2;
  long long d = 1;
  t[9] = "7332";
  t[8] = "7222";
  t[7] = "7";
  t[6] = "53";
  t[5] = "5";
  t[4] = "322";
  t[3] = "3";
  t[2] = "2";
  string s = "";
  for (int k = 1; k <= n; ++k) s = s + t[a[k] - '0'];
  sort(s.begin(), s.end());
  reverse(s.begin(), s.end());
  cout << s;
  return 0;
}

```