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 gcd(int a, int b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  string s;
  cin >> s;
  vector<int> a(10, 0);
  for (char i : s) {
    if (i == '4') {
      a[3]++;
      a[2] += 2;
    } else if (i == '8') {
      a[7]++;
      a[2] += 3;
    } else if (i == '9') {
      a[3] += 2;
      a[2]++;
      a[7]++;
    } else if (i == '6') {
      a[3]++;
      a[5]++;
    } else {
      int no = (int)i - 48;
      a[no]++;
    }
  }
  for (int i = 7; i != 1; i--) {
    while (a[i] != 0) {
      cout << i;
      a[i]--;
    }
  }
  cout << "\n";
  return 0;
}
