#include <bits/stdc++.h>
using namespace std;
inline long long getnum() {
  char c = getchar();
  long long num, sign = 1;
  for (; c < '0' || c > '9'; c = getchar())
    if (c == '-') sign = -1;
  for (num = 0; c >= '0' && c <= '9';) {
    c -= '0';
    num = num * 10 + c;
    c = getchar();
  }
  return num * sign;
}
vector<long long> V;
int main() {
  long long n = getnum(), N = getnum();
  for (; N > 0; N = N / 10) {
    long long x = N % 10;
    if (x == 4) {
      V.push_back(3);
      V.push_back(2);
      V.push_back(2);
    } else if (x == 6) {
      V.push_back(5);
      V.push_back(3);
    } else if (x == 8) {
      V.push_back(7);
      V.push_back(2);
      V.push_back(2);
      V.push_back(2);
    } else if (x == 9) {
      V.push_back(7);
      V.push_back(3);
      V.push_back(3);
      V.push_back(2);
    } else if (x > 1) {
      V.push_back(x);
    }
  }
  sort(V.begin(), V.end());
  reverse(V.begin(), V.end());
  for (int i = 0; i < V.size(); i++) printf("%d", V[i]);
}

### 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;
inline long long getnum() {
  char c = getchar();
  long long num, sign = 1;
  for (; c < '0' || c > '9'; c = getchar())
    if (c == '-') sign = -1;
  for (num = 0; c >= '0' && c <= '9';) {
    c -= '0';
    num = num * 10 + c;
    c = getchar();
  }
  return num * sign;
}
vector<long long> V;
int main() {
  long long n = getnum(), N = getnum();
  for (; N > 0; N = N / 10) {
    long long x = N % 10;
    if (x == 4) {
      V.push_back(3);
      V.push_back(2);
      V.push_back(2);
    } else if (x == 6) {
      V.push_back(5);
      V.push_back(3);
    } else if (x == 8) {
      V.push_back(7);
      V.push_back(2);
      V.push_back(2);
      V.push_back(2);
    } else if (x == 9) {
      V.push_back(7);
      V.push_back(3);
      V.push_back(3);
      V.push_back(2);
    } else if (x > 1) {
      V.push_back(x);
    }
  }
  sort(V.begin(), V.end());
  reverse(V.begin(), V.end());
  for (int i = 0; i < V.size(); i++) printf("%d", V[i]);
}

```