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;
const vector<int> FOUR = {3, 2, 2};
const vector<int> SIX = {5, 3};
const vector<int> EIGHT = {7, 2, 2, 2};
const vector<int> NINE = {7, 3, 3, 2};
int n;
vector<int> acc;
int main() {
  ios_base::sync_with_stdio(0);
  cin >> n;
  for (int i = 0; i < n; ++i) {
    char c;
    cin >> c;
    int x = c - '0';
    if (x > 1) {
      if (x == 4)
        acc.insert(acc.end(), FOUR.begin(), FOUR.end());
      else if (x == 6)
        acc.insert(acc.end(), SIX.begin(), SIX.end());
      else if (x == 8)
        acc.insert(acc.end(), EIGHT.begin(), EIGHT.end());
      else if (x == 9)
        acc.insert(acc.end(), NINE.begin(), NINE.end());
      else
        acc.push_back(x);
    }
  }
  sort(acc.begin(), acc.end());
  reverse(acc.begin(), acc.end());
  for (int x : acc) cout << x;
  cout << endl;
  return 0;
}
