#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  long long x;
  cin >> x;
  int largest_prime = 0;
  int p[n];
  int a = 0, b = 0, c = 0, d = 0;
  for (int i = 0; i < n; i++) {
    p[i] = x % 10;
    x /= 10;
    if (p[i] == 2) a++;
    if (p[i] == 3) {
      a++;
      b++;
    }
    if (p[i] == 4) {
      a += 3;
      b++;
    }
    if (p[i] == 5) {
      c++;
      a += 3;
      b++;
    }
    if (p[i] == 6) {
      c++;
      a += 4;
      b += 2;
    }
    if (p[i] == 7) {
      d++;
      c++;
      a += 4;
      b += 2;
    }
    if (p[i] == 8) {
      d++;
      c++;
      a += 7;
      b += 2;
    }
    if (p[i] == 9) {
      d++;
      c++;
      a += 7;
      b += 4;
    }
  }
  string s = "";
  if (d == 0)
    ;
  else {
    while (d--) {
      s += '7';
      a -= 4;
      b -= 2;
      c -= 1;
    }
  }
  if (c == 0) {
  } else {
    while (c--) {
      s += '5';
      a -= 3;
      b -= 1;
    }
  }
  if (b == 0) {
  } else {
    while (b--) {
      s += '3';
      a -= 1;
    }
  }
  if (a == 0) {
    cout << s;
  } else {
    while (a--) {
      s += '2';
    }
    cout << s;
  }
}

### Prompt

Please provide a CPP coded solution to the problem described below:

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 main() {
  int n;
  cin >> n;
  long long x;
  cin >> x;
  int largest_prime = 0;
  int p[n];
  int a = 0, b = 0, c = 0, d = 0;
  for (int i = 0; i < n; i++) {
    p[i] = x % 10;
    x /= 10;
    if (p[i] == 2) a++;
    if (p[i] == 3) {
      a++;
      b++;
    }
    if (p[i] == 4) {
      a += 3;
      b++;
    }
    if (p[i] == 5) {
      c++;
      a += 3;
      b++;
    }
    if (p[i] == 6) {
      c++;
      a += 4;
      b += 2;
    }
    if (p[i] == 7) {
      d++;
      c++;
      a += 4;
      b += 2;
    }
    if (p[i] == 8) {
      d++;
      c++;
      a += 7;
      b += 2;
    }
    if (p[i] == 9) {
      d++;
      c++;
      a += 7;
      b += 4;
    }
  }
  string s = "";
  if (d == 0)
    ;
  else {
    while (d--) {
      s += '7';
      a -= 4;
      b -= 2;
      c -= 1;
    }
  }
  if (c == 0) {
  } else {
    while (c--) {
      s += '5';
      a -= 3;
      b -= 1;
    }
  }
  if (b == 0) {
  } else {
    while (b--) {
      s += '3';
      a -= 1;
    }
  }
  if (a == 0) {
    cout << s;
  } else {
    while (a--) {
      s += '2';
    }
    cout << s;
  }
}

```