#include <bits/stdc++.h>
using namespace std;
map<int, int> m, n;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int k;
  m[2] = 0;
  n[0] = 2;
  m[3] = 1;
  n[1] = 3;
  m[5] = 2;
  n[2] = 5;
  m[7] = 3;
  n[3] = 7;
  cin >> k;
  string s;
  cin >> s;
  vector<int> power(4, 0);
  vector<vector<int>> pow = {{0}, {1},    {2}, {3},       {2, 2},
                             {5}, {2, 3}, {7}, {2, 2, 2}, {3, 3}};
  for (int i = 0; i < k; i++) {
    int x = s[i] - '0';
    if (x == 0 || x == 1) {
      continue;
    } else {
      for (int i = x; i >= 2; i--) {
        for (int j : pow[i]) {
          power[m[j]]++;
        }
      }
    }
  }
  string ans;
  for (int i = 3; i >= 0; i--) {
    if (power[i]) {
      int t = power[i];
      for (int j = 0; j < t; j++) {
        ans += '0' + (n[i]);
        for (int x = n[i]; x >= 2; x--) {
          for (int l : pow[x]) {
            power[m[l]]--;
          }
        }
      }
    }
  }
  cout << ans;
  return 0;
}

### Prompt

Your task is to create 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;
map<int, int> m, n;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int k;
  m[2] = 0;
  n[0] = 2;
  m[3] = 1;
  n[1] = 3;
  m[5] = 2;
  n[2] = 5;
  m[7] = 3;
  n[3] = 7;
  cin >> k;
  string s;
  cin >> s;
  vector<int> power(4, 0);
  vector<vector<int>> pow = {{0}, {1},    {2}, {3},       {2, 2},
                             {5}, {2, 3}, {7}, {2, 2, 2}, {3, 3}};
  for (int i = 0; i < k; i++) {
    int x = s[i] - '0';
    if (x == 0 || x == 1) {
      continue;
    } else {
      for (int i = x; i >= 2; i--) {
        for (int j : pow[i]) {
          power[m[j]]++;
        }
      }
    }
  }
  string ans;
  for (int i = 3; i >= 0; i--) {
    if (power[i]) {
      int t = power[i];
      for (int j = 0; j < t; j++) {
        ans += '0' + (n[i]);
        for (int x = n[i]; x >= 2; x--) {
          for (int l : pow[x]) {
            power[m[l]]--;
          }
        }
      }
    }
  }
  cout << ans;
  return 0;
}

```