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 main() {
  ios_base::sync_with_stdio(0);
  int n;
  string x;
  vector<int> res;
  cin >> n >> x;
  int k = 0;
  while (x[k] == '0') k++;
  for (int i = k; i < n; i++) {
    if (x[i] == '1') continue;
    if (x[i] == '7' || x[i] == '5' || x[i] == '2' || x[i] == '3')
      res.push_back(x[i] - '0');
    else {
      if (x[i] == '4') {
        res.push_back(2), res.push_back(2), res.push_back(3);
      } else if (x[i] == '6') {
        res.push_back(3), res.push_back(5);
      } else if (x[i] == '8') {
        res.push_back(2), res.push_back(2), res.push_back(2);
        res.push_back(7);
      } else if (x[i] == '9') {
        res.push_back(7);
        res.push_back(2), res.push_back(3), res.push_back(3);
      }
    }
  }
  sort(res.begin(), res.end());
  for (int i = res.size() - 1; i >= 0; i--) {
    cout << res[i];
  }
  return 0;
}
