#include <bits/stdc++.h>
using namespace std;
const long long maxn = 2e5 + 500;
const long long mod = 1e9 + 7;
const long long INF = 1e18 + 1;
vector<long long> cons(char y) {
  long long z = y - '0';
  if (z == 0 || z == 1) return {};
  vector<long long> to_ret;
  for (long long i = 2; i <= z; i++) {
    while (z % i == 0) {
      to_ret.push_back(i);
      z /= i;
    }
  }
  return to_ret;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> n;
  vector<long long> ans;
  for (long long i = 0; i < n; i++) {
    char x;
    cin >> x;
    if (x == '0' || x == '1')
      ;
    else if (x == '2' || x == '3' || x == '5' || x == '7')
      ans.push_back(x - '0');
    else if (x == '4')
      ans.insert(ans.end(), {2, 2, 3});
    else if (x == '8')
      ans.insert(ans.end(), {2, 2, 2, 7});
    else if (x == '9')
      ans.insert(ans.end(), {3, 3, 2, 7});
    else if (x == '6')
      ans.insert(ans.end(), {3, 5});
  }
  sort(ans.rbegin(), ans.rend());
  for (long long i : ans) {
    cout << i;
  }
  return 0;
}

### Prompt

Your challenge is to write 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;
const long long maxn = 2e5 + 500;
const long long mod = 1e9 + 7;
const long long INF = 1e18 + 1;
vector<long long> cons(char y) {
  long long z = y - '0';
  if (z == 0 || z == 1) return {};
  vector<long long> to_ret;
  for (long long i = 2; i <= z; i++) {
    while (z % i == 0) {
      to_ret.push_back(i);
      z /= i;
    }
  }
  return to_ret;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> n;
  vector<long long> ans;
  for (long long i = 0; i < n; i++) {
    char x;
    cin >> x;
    if (x == '0' || x == '1')
      ;
    else if (x == '2' || x == '3' || x == '5' || x == '7')
      ans.push_back(x - '0');
    else if (x == '4')
      ans.insert(ans.end(), {2, 2, 3});
    else if (x == '8')
      ans.insert(ans.end(), {2, 2, 2, 7});
    else if (x == '9')
      ans.insert(ans.end(), {3, 3, 2, 7});
    else if (x == '6')
      ans.insert(ans.end(), {3, 5});
  }
  sort(ans.rbegin(), ans.rend());
  for (long long i : ans) {
    cout << i;
  }
  return 0;
}

```