#include <bits/stdc++.h>
using namespace std;
long long int fact[20][20] = {{},  {1},    {2}, {3},          {3, 2, 2},
                              {5}, {3, 5}, {7}, {2, 2, 2, 7}, {2, 3, 3, 7}};
long long int val[20] = {0, 0, 1, 1, 3, 1, 2, 1, 4, 4};
int main() {
  long long int n;
  scanf("%lld", &n);
  string s;
  long long int i, j;
  for (i = 2; i <= 9; i++) {
    for (j = 0; j < val[i]; j++) {
    }
  }
  cin >> s;
  vector<long long int> v;
  for (i = 0; i < n; i++) {
    long long int va = s[i] - '0';
    if (va > 1) {
      for (j = 0; j < val[va]; j++) {
        v.push_back(fact[va][j]);
      }
    }
  }
  sort(v.begin(), v.end());
  for (i = v.size() - 1; i >= 0; i--) cout << v[i];
}

### 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>
using namespace std;
long long int fact[20][20] = {{},  {1},    {2}, {3},          {3, 2, 2},
                              {5}, {3, 5}, {7}, {2, 2, 2, 7}, {2, 3, 3, 7}};
long long int val[20] = {0, 0, 1, 1, 3, 1, 2, 1, 4, 4};
int main() {
  long long int n;
  scanf("%lld", &n);
  string s;
  long long int i, j;
  for (i = 2; i <= 9; i++) {
    for (j = 0; j < val[i]; j++) {
    }
  }
  cin >> s;
  vector<long long int> v;
  for (i = 0; i < n; i++) {
    long long int va = s[i] - '0';
    if (va > 1) {
      for (j = 0; j < val[va]; j++) {
        v.push_back(fact[va][j]);
      }
    }
  }
  sort(v.begin(), v.end());
  for (i = v.size() - 1; i >= 0; i--) cout << v[i];
}

```