#include <bits/stdc++.h>
using namespace std;
int power[10];
int count_power(int d, int f) {
  int n = 0;
  while (d) {
    d /= f;
    n += d;
  }
  return n;
}
int main() {
  int n;
  string s;
  cin >> n >> s;
  for (int i = 0; i < n; i++) {
    int d = s[i] - '0';
    power[2] += count_power(d, 2);
    power[3] += count_power(d, 3);
    power[5] += count_power(d, 5);
    power[7] += count_power(d, 7);
  }
  string r;
  while (power[7]) {
    r.push_back('7');
    power[7]--;
    power[5]--;
    power[3] -= 2;
    power[2] -= 4;
  }
  while (power[5]) {
    r.push_back('5');
    power[5]--;
    power[3]--;
    power[2] -= 3;
  }
  while (power[3]) {
    r.push_back('3');
    power[3]--;
    power[2]--;
  }
  while (power[2]) {
    r.push_back('2');
    power[2]--;
  }
  cout << r << endl;
  return 0;
}

### Prompt

Your task is to create a Cpp solution to the following problem:

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>

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int power[10];
int count_power(int d, int f) {
  int n = 0;
  while (d) {
    d /= f;
    n += d;
  }
  return n;
}
int main() {
  int n;
  string s;
  cin >> n >> s;
  for (int i = 0; i < n; i++) {
    int d = s[i] - '0';
    power[2] += count_power(d, 2);
    power[3] += count_power(d, 3);
    power[5] += count_power(d, 5);
    power[7] += count_power(d, 7);
  }
  string r;
  while (power[7]) {
    r.push_back('7');
    power[7]--;
    power[5]--;
    power[3] -= 2;
    power[2] -= 4;
  }
  while (power[5]) {
    r.push_back('5');
    power[5]--;
    power[3]--;
    power[2] -= 3;
  }
  while (power[3]) {
    r.push_back('3');
    power[3]--;
    power[2]--;
  }
  while (power[2]) {
    r.push_back('2');
    power[2]--;
  }
  cout << r << endl;
  return 0;
}

```