#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, y, i;
  string str;
  cin >> n;
  cin >> str;
  queue<int> que;
  int arr[4] = {7, 5, 3, 2};
  int stor[11][4] = {{0, 0, 0, 0}, {0, 0, 0, 0}, {1, 0, 0, 0}, {1, 1, 0, 0},
                     {3, 1, 0, 0}, {3, 1, 1, 0}, {4, 2, 1, 0}, {4, 2, 1, 1},
                     {7, 2, 1, 1}, {7, 4, 1, 1}};
  map<int, int> tot;
  for (auto c : str) {
    y = int(c - 48);
    tot[2] += stor[y][0];
    tot[3] += stor[y][1];
    tot[5] += stor[y][2];
    tot[7] += stor[y][3];
  }
  for (auto y : arr) {
    for (i = tot[y]; i > 0; --i) que.push(y);
    tot[2] -= (stor[y][0] * tot[y]);
    tot[3] -= (stor[y][1] * tot[y]);
    tot[5] -= (stor[y][2] * tot[y]);
    tot[7] -= (stor[y][3] * tot[y]);
  }
  while (!que.empty()) {
    cout << que.front();
    que.pop();
  }
}

### 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;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, y, i;
  string str;
  cin >> n;
  cin >> str;
  queue<int> que;
  int arr[4] = {7, 5, 3, 2};
  int stor[11][4] = {{0, 0, 0, 0}, {0, 0, 0, 0}, {1, 0, 0, 0}, {1, 1, 0, 0},
                     {3, 1, 0, 0}, {3, 1, 1, 0}, {4, 2, 1, 0}, {4, 2, 1, 1},
                     {7, 2, 1, 1}, {7, 4, 1, 1}};
  map<int, int> tot;
  for (auto c : str) {
    y = int(c - 48);
    tot[2] += stor[y][0];
    tot[3] += stor[y][1];
    tot[5] += stor[y][2];
    tot[7] += stor[y][3];
  }
  for (auto y : arr) {
    for (i = tot[y]; i > 0; --i) que.push(y);
    tot[2] -= (stor[y][0] * tot[y]);
    tot[3] -= (stor[y][1] * tot[y]);
    tot[5] -= (stor[y][2] * tot[y]);
    tot[7] -= (stor[y][3] * tot[y]);
  }
  while (!que.empty()) {
    cout << que.front();
    que.pop();
  }
}

```