#include <bits/stdc++.h>
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
signed main() {
  long long int n;
  cin >> n;
  vector<long long int> cnt(10);
  vector<long long int> ans;
  for (long long int i = 0; i < n; i++) {
    char c;
    cin >> c;
    long long int num = c - '0';
    if (num == 0 || num == 1) continue;
    if (num == 2) {
      ans.push_back(2);
    } else if (num == 3) {
      ans.push_back(3);
    } else if (num == 4) {
      ans.push_back(3);
      ans.push_back(2);
      ans.push_back(2);
    } else if (num == 5) {
      ans.push_back(5);
    } else if (num == 6) {
      ans.push_back(5);
      ans.push_back(3);
    } else if (num == 7) {
      ans.push_back(7);
    } else if (num == 8) {
      ans.push_back(7);
      ans.push_back(2);
      ans.push_back(2);
      ans.push_back(2);
    } else {
      ans.push_back(7);
      ans.push_back(3);
      ans.push_back(3);
      ans.push_back(2);
    }
  }
  sort(ans.begin(), ans.end());
  for (long long int i = (long long int)ans.size() - 1; i >= 0; i--)
    cout << ans[i];
  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>
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
signed main() {
  long long int n;
  cin >> n;
  vector<long long int> cnt(10);
  vector<long long int> ans;
  for (long long int i = 0; i < n; i++) {
    char c;
    cin >> c;
    long long int num = c - '0';
    if (num == 0 || num == 1) continue;
    if (num == 2) {
      ans.push_back(2);
    } else if (num == 3) {
      ans.push_back(3);
    } else if (num == 4) {
      ans.push_back(3);
      ans.push_back(2);
      ans.push_back(2);
    } else if (num == 5) {
      ans.push_back(5);
    } else if (num == 6) {
      ans.push_back(5);
      ans.push_back(3);
    } else if (num == 7) {
      ans.push_back(7);
    } else if (num == 8) {
      ans.push_back(7);
      ans.push_back(2);
      ans.push_back(2);
      ans.push_back(2);
    } else {
      ans.push_back(7);
      ans.push_back(3);
      ans.push_back(3);
      ans.push_back(2);
    }
  }
  sort(ans.begin(), ans.end());
  for (long long int i = (long long int)ans.size() - 1; i >= 0; i--)
    cout << ans[i];
  return 0;
}

```