#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
template <class c>
struct rge {
  c b, e;
};
template <class c>
rge<c> range(c i, c j) {
  return rge<c>{i, j};
}
template <class c>
auto dud(c *x) -> decltype(cerr << *x, 0);
template <class c>
char dud(...);
struct debug {
  template <class c>
  debug &operator<<(const c &) {
    return *this;
  }
};
const long long MOD = 1e9 + 7;
const long long N = 1e5 + 10;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  string arr[] = {"",  "",     "2",   "3", "322", "5", arr[3] + arr[5],
                  "7", "7222", "7332"};
  int x;
  cin >> x;
  string ans;
  string n;
  cin >> n;
  for (int i = 0; i < x; i++) {
    ans += arr[n[i] - '0'];
  }
  sort(ans.begin(), ans.end());
  reverse(ans.begin(), ans.end());
  cout << ans << '\n';
  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>
#pragma GCC optimize("O3")
using namespace std;
template <class c>
struct rge {
  c b, e;
};
template <class c>
rge<c> range(c i, c j) {
  return rge<c>{i, j};
}
template <class c>
auto dud(c *x) -> decltype(cerr << *x, 0);
template <class c>
char dud(...);
struct debug {
  template <class c>
  debug &operator<<(const c &) {
    return *this;
  }
};
const long long MOD = 1e9 + 7;
const long long N = 1e5 + 10;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  string arr[] = {"",  "",     "2",   "3", "322", "5", arr[3] + arr[5],
                  "7", "7222", "7332"};
  int x;
  cin >> x;
  string ans;
  string n;
  cin >> n;
  for (int i = 0; i < x; i++) {
    ans += arr[n[i] - '0'];
  }
  sort(ans.begin(), ans.end());
  reverse(ans.begin(), ans.end());
  cout << ans << '\n';
  return 0;
}

```