#include <bits/stdc++.h>
using namespace std;
long long expo(long long x, long long y) {
  long long res = 1;
  while (y) {
    if (y & 1) res = res * x;
    res %= 1000000007;
    y = y >> 1;
    x = x * x;
    x %= 1000000007;
  }
  return res;
}
const int N = 2e5 + 5;
vector<long long> adj[N];
long long A[N];
long long n;
void solve() {
  long long i, j;
  cin >> n;
  vector<long long> vc;
  string s;
  cin >> s;
  for (i = 0; i < int((s).size()); i++) {
    long long r = s[i] - '0';
    if (r <= 1) continue;
    if (r == 2 || r == 3 || r == 5 || r == 7) vc.push_back(r);
    if (r == 4) {
      vc.push_back(3);
      vc.push_back(2);
      vc.push_back(2);
    }
    if (r == 6) {
      vc.push_back(5);
      vc.push_back(3);
    }
    if (r == 8) {
      vc.push_back(7);
      vc.push_back(2);
      vc.push_back(2);
      vc.push_back(2);
    }
    if (r == 9) {
      vc.push_back(7);
      vc.push_back(3);
      vc.push_back(3);
      vc.push_back(2);
    }
  }
  sort(vc.begin(), vc.end(), greater<long long>());
  for (auto e : vc) cout << e;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
  ;
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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 expo(long long x, long long y) {
  long long res = 1;
  while (y) {
    if (y & 1) res = res * x;
    res %= 1000000007;
    y = y >> 1;
    x = x * x;
    x %= 1000000007;
  }
  return res;
}
const int N = 2e5 + 5;
vector<long long> adj[N];
long long A[N];
long long n;
void solve() {
  long long i, j;
  cin >> n;
  vector<long long> vc;
  string s;
  cin >> s;
  for (i = 0; i < int((s).size()); i++) {
    long long r = s[i] - '0';
    if (r <= 1) continue;
    if (r == 2 || r == 3 || r == 5 || r == 7) vc.push_back(r);
    if (r == 4) {
      vc.push_back(3);
      vc.push_back(2);
      vc.push_back(2);
    }
    if (r == 6) {
      vc.push_back(5);
      vc.push_back(3);
    }
    if (r == 8) {
      vc.push_back(7);
      vc.push_back(2);
      vc.push_back(2);
      vc.push_back(2);
    }
    if (r == 9) {
      vc.push_back(7);
      vc.push_back(3);
      vc.push_back(3);
      vc.push_back(2);
    }
  }
  sort(vc.begin(), vc.end(), greater<long long>());
  for (auto e : vc) cout << e;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
  ;
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}

```