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>
#include <bits/stdc++.h>
using namespace std;
int n;
string num;
vector<int> answer;
void add(char x) {
  switch (x) {
    case '0':
    case '1':
      break;
    case '2':
      answer.push_back(2);
      break;
    case '3':
      answer.push_back(3);
      break;
    case '4':
      answer.push_back(3);
      answer.push_back(2);
      answer.push_back(2);
      break;
    case '5':
      answer.push_back(5);
      break;
    case '6':
      answer.push_back(5);
      answer.push_back(3);
      break;
    case '7':
      answer.push_back(7);
      break;
    case '8':
      answer.push_back(7);
      answer.push_back(2);
      answer.push_back(2);
      answer.push_back(2);
      break;
    case '9':
      answer.push_back(7);
      answer.push_back(3);
      answer.push_back(3);
      answer.push_back(2);
      break;
  }
}
int main(void) {
  cin >> n >> num;
  for (int i = 0; i < n; i++) add(num[i]);
  sort(answer.begin(), answer.end(), greater<int>());
  for (int i = 0; i < answer.size(); i++) cout << answer[i];
  cout << endl;
  return 0;
}
