#include <bits/stdc++.h>
using namespace std;
bool cmp(long long x, long long y) { return x > y; }
int main() {
  long long n;
  cin >> n;
  string S;
  cin >> S;
  vector<long long> C;
  for (long long i = 0; i < n; i++) {
    long long x = S[i] - '0';
    if (x == 0 || x == 1)
      continue;
    else if (x == 2)
      C.push_back(2);
    else if (x == 3)
      C.push_back(3);
    else if (x == 4)
      C.push_back(2), C.push_back(2), C.push_back(3);
    else if (x == 5)
      C.push_back(5);
    else if (x == 6)
      C.push_back(5), C.push_back(3);
    else if (x == 7)
      C.push_back(7);
    else if (x == 8)
      C.push_back(7), C.push_back(2), C.push_back(2), C.push_back(2);
    else if (x == 9)
      C.push_back(7), C.push_back(3), C.push_back(3), C.push_back(2);
  }
  sort(C.begin(), C.end(), cmp);
  for (auto it : C) cout << it;
}

### Prompt

Construct a CPP code solution to the problem outlined:

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;
bool cmp(long long x, long long y) { return x > y; }
int main() {
  long long n;
  cin >> n;
  string S;
  cin >> S;
  vector<long long> C;
  for (long long i = 0; i < n; i++) {
    long long x = S[i] - '0';
    if (x == 0 || x == 1)
      continue;
    else if (x == 2)
      C.push_back(2);
    else if (x == 3)
      C.push_back(3);
    else if (x == 4)
      C.push_back(2), C.push_back(2), C.push_back(3);
    else if (x == 5)
      C.push_back(5);
    else if (x == 6)
      C.push_back(5), C.push_back(3);
    else if (x == 7)
      C.push_back(7);
    else if (x == 8)
      C.push_back(7), C.push_back(2), C.push_back(2), C.push_back(2);
    else if (x == 9)
      C.push_back(7), C.push_back(3), C.push_back(3), C.push_back(2);
  }
  sort(C.begin(), C.end(), cmp);
  for (auto it : C) cout << it;
}

```