#include <bits/stdc++.h>
using namespace std;
int N;
string s;
int pows[4] = {0, 0, 0, 0};
void Desc(int q) {
  if (q <= 1) return;
  switch (q) {
    case 2:
      pows[0]--;
      break;
    case 3:
      pows[1]--;
      break;
    case 4:
      pows[0] -= 2;
      break;
    case 5:
      pows[2]--;
      break;
    case 6:
      pows[0]--;
      pows[1]--;
      break;
    case 7:
      pows[3]--;
      break;
    case 8:
      pows[0] -= 3;
      break;
    case 9:
      pows[1] -= 2;
      break;
  }
  Desc(q - 1);
}
void Proc(int q) {
  if (q <= 1) return;
  switch (q) {
    case 2:
      pows[0]++;
      break;
    case 3:
      pows[1]++;
      break;
    case 4:
      pows[0] += 2;
      break;
    case 5:
      pows[2]++;
      break;
    case 6:
      pows[0]++;
      pows[1]++;
      break;
    case 7:
      pows[3]++;
      break;
    case 8:
      pows[0] += 3;
      break;
    case 9:
      pows[1] += 2;
      break;
  }
  Proc(q - 1);
}
int conv(int q) {
  switch (q) {
    case 0:
      return 2;
    case 1:
      return 3;
    case 2:
      return 5;
    case 3:
      return 7;
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cout.precision(20);
  cin >> N;
  cin >> s;
  for (int i = 0; i < N; ++i) Proc(s[i] - '0');
  for (int i = 3; i >= 0; --i) {
    while (pows[i] != 0) {
      cout << conv(i);
      Desc(conv(i));
    }
  }
  return 0;
}

### Prompt

Your challenge is to write 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;
string s;
int pows[4] = {0, 0, 0, 0};
void Desc(int q) {
  if (q <= 1) return;
  switch (q) {
    case 2:
      pows[0]--;
      break;
    case 3:
      pows[1]--;
      break;
    case 4:
      pows[0] -= 2;
      break;
    case 5:
      pows[2]--;
      break;
    case 6:
      pows[0]--;
      pows[1]--;
      break;
    case 7:
      pows[3]--;
      break;
    case 8:
      pows[0] -= 3;
      break;
    case 9:
      pows[1] -= 2;
      break;
  }
  Desc(q - 1);
}
void Proc(int q) {
  if (q <= 1) return;
  switch (q) {
    case 2:
      pows[0]++;
      break;
    case 3:
      pows[1]++;
      break;
    case 4:
      pows[0] += 2;
      break;
    case 5:
      pows[2]++;
      break;
    case 6:
      pows[0]++;
      pows[1]++;
      break;
    case 7:
      pows[3]++;
      break;
    case 8:
      pows[0] += 3;
      break;
    case 9:
      pows[1] += 2;
      break;
  }
  Proc(q - 1);
}
int conv(int q) {
  switch (q) {
    case 0:
      return 2;
    case 1:
      return 3;
    case 2:
      return 5;
    case 3:
      return 7;
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cout.precision(20);
  cin >> N;
  cin >> s;
  for (int i = 0; i < N; ++i) Proc(s[i] - '0');
  for (int i = 3; i >= 0; --i) {
    while (pows[i] != 0) {
      cout << conv(i);
      Desc(conv(i));
    }
  }
  return 0;
}

```