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;
void read() {
  char x;
  int n;
  cin >> n;
  vector<int> res;
  for (int i = 0; i < n; ++i) {
    cin.get(x);
    if (!isdigit(x)) i--;
    if (x == '0' && x == '1') continue;
    if (x == '2' || x == '3' || x == '5' || x == '7') res.push_back((x - '0'));
    if (x == '4') res.push_back(3), res.push_back(2), res.push_back(2);
    if (x == '6') res.push_back(5), res.push_back(3);
    if (x == '8')
      res.push_back(7), res.push_back(2), res.push_back(2), res.push_back(2);
    if (x == '9')
      res.push_back(7), res.push_back(3), res.push_back(3), res.push_back(2);
  }
  sort(res.begin(), res.end(), greater<int>());
  for (auto it : res) cout << it;
}
int main() {
  read();
  return 0;
}
