#include <bits/stdc++.h>
using namespace std;
int n;
char a;
int cnt2, cnt3, cnt5, cnt7;
int main() {
  int i;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> a;
    if (a == '2') cnt2++;
    if (a == '3') {
      cnt2++;
      cnt3++;
    }
    if (a == '4') {
      cnt2 += 3;
      cnt3++;
    }
    if (a == '5') {
      cnt2 += 3;
      cnt3++;
      cnt5++;
    }
    if (a == '6') {
      cnt2 += 4;
      cnt3 += 2;
      cnt5++;
    }
    if (a == '7') {
      cnt2 += 4;
      cnt3 += 2;
      cnt5++;
      cnt7++;
    }
    if (a == '8') {
      cnt2 += 7;
      cnt3 += 2;
      cnt5++;
      cnt7++;
    }
    if (a == '9') {
      cnt2 += 7;
      cnt3 += 4;
      cnt5++;
      cnt7++;
    }
  }
  for (i = 0; i < cnt7; i++) cout << 7;
  cnt2 -= cnt7 * 4;
  cnt3 -= cnt7 * 2;
  cnt5 -= cnt7;
  for (i = 0; i < cnt5; i++) cout << 5;
  cnt2 -= cnt5 * 3;
  cnt3 -= cnt5;
  for (i = 0; i < cnt3; i++) cout << 3;
  cnt2 -= cnt3;
  for (i = 0; i < cnt2; i++) cout << 2;
  cout << '\n';
  return 0;
}

### Prompt

Generate 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 n;
char a;
int cnt2, cnt3, cnt5, cnt7;
int main() {
  int i;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> a;
    if (a == '2') cnt2++;
    if (a == '3') {
      cnt2++;
      cnt3++;
    }
    if (a == '4') {
      cnt2 += 3;
      cnt3++;
    }
    if (a == '5') {
      cnt2 += 3;
      cnt3++;
      cnt5++;
    }
    if (a == '6') {
      cnt2 += 4;
      cnt3 += 2;
      cnt5++;
    }
    if (a == '7') {
      cnt2 += 4;
      cnt3 += 2;
      cnt5++;
      cnt7++;
    }
    if (a == '8') {
      cnt2 += 7;
      cnt3 += 2;
      cnt5++;
      cnt7++;
    }
    if (a == '9') {
      cnt2 += 7;
      cnt3 += 4;
      cnt5++;
      cnt7++;
    }
  }
  for (i = 0; i < cnt7; i++) cout << 7;
  cnt2 -= cnt7 * 4;
  cnt3 -= cnt7 * 2;
  cnt5 -= cnt7;
  for (i = 0; i < cnt5; i++) cout << 5;
  cnt2 -= cnt5 * 3;
  cnt3 -= cnt5;
  for (i = 0; i < cnt3; i++) cout << 3;
  cnt2 -= cnt3;
  for (i = 0; i < cnt2; i++) cout << 2;
  cout << '\n';
  return 0;
}

```