#include <bits/stdc++.h>
using namespace std;
long long stoi(string s) {
  long long l = s.length();
  long long n = 0;
  for (long long i = 0; i < l; i++) {
    n = n * 10 + s[i] - '0';
  }
  return n;
}
int main() {
  long long i, j, num[100005], n, y;
  char str[100005];
  string ans, x;
  map<long long, string> m;
  m[0] = "";
  m[1] = "";
  m[2] = "2";
  m[3] = "3";
  m[4] = "322";
  m[5] = "5";
  m[6] = "53";
  m[7] = "7";
  m[8] = "7222";
  m[9] = "7332";
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> str[i];
    num[i] = str[i] - '0';
  }
  ans = "";
  x = "";
  y = 0;
  string::size_type sz = 0;
  for (i = 0; i < n; i++) {
    y = 0;
    x = "";
    ans += m[num[i]];
  }
  sort(ans.rbegin(), ans.rend());
  cout << ans;
  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;
long long stoi(string s) {
  long long l = s.length();
  long long n = 0;
  for (long long i = 0; i < l; i++) {
    n = n * 10 + s[i] - '0';
  }
  return n;
}
int main() {
  long long i, j, num[100005], n, y;
  char str[100005];
  string ans, x;
  map<long long, string> m;
  m[0] = "";
  m[1] = "";
  m[2] = "2";
  m[3] = "3";
  m[4] = "322";
  m[5] = "5";
  m[6] = "53";
  m[7] = "7";
  m[8] = "7222";
  m[9] = "7332";
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> str[i];
    num[i] = str[i] - '0';
  }
  ans = "";
  x = "";
  y = 0;
  string::size_type sz = 0;
  for (i = 0; i < n; i++) {
    y = 0;
    x = "";
    ans += m[num[i]];
  }
  sort(ans.rbegin(), ans.rend());
  cout << ans;
  return 0;
}

```