#include <bits/stdc++.h>
using namespace std;
char x[20];
int n, i, j;
vector<char> ans;
bool comp(char a, char b) { return int(a) > int(b); }
int main() {
  scanf("%d", &n);
  scanf("%s", &x);
  for (i = 0; i < strlen(x); i++) {
    if (x[i] == '1' || x[i] == '0')
      continue;
    else if (x[i] == '4') {
      ans.push_back('3');
      for (int z = 1; z <= 2; z++) ans.push_back('2');
    } else if (x[i] == '6') {
      ans.push_back('5');
      ans.push_back('3');
    } else if (x[i] == '8') {
      ans.push_back('7');
      for (int z = 0; z < 3; z++) ans.push_back('2');
    } else if (x[i] == '9') {
      ans.push_back('7');
      for (int z = 1; z <= 2; z++) ans.push_back('3');
      ans.push_back('2');
    } else
      ans.push_back(x[i]);
  }
  sort(ans.begin(), ans.end(), comp);
  for (i = 0; i < ans.size(); i++) printf("%c", ans[i]);
  printf("\n");
  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;
char x[20];
int n, i, j;
vector<char> ans;
bool comp(char a, char b) { return int(a) > int(b); }
int main() {
  scanf("%d", &n);
  scanf("%s", &x);
  for (i = 0; i < strlen(x); i++) {
    if (x[i] == '1' || x[i] == '0')
      continue;
    else if (x[i] == '4') {
      ans.push_back('3');
      for (int z = 1; z <= 2; z++) ans.push_back('2');
    } else if (x[i] == '6') {
      ans.push_back('5');
      ans.push_back('3');
    } else if (x[i] == '8') {
      ans.push_back('7');
      for (int z = 0; z < 3; z++) ans.push_back('2');
    } else if (x[i] == '9') {
      ans.push_back('7');
      for (int z = 1; z <= 2; z++) ans.push_back('3');
      ans.push_back('2');
    } else
      ans.push_back(x[i]);
  }
  sort(ans.begin(), ans.end(), comp);
  for (i = 0; i < ans.size(); i++) printf("%c", ans[i]);
  printf("\n");
  return 0;
}

```