#include <bits/stdc++.h>
using namespace std;
template <typename T>
struct Pt {
  T x, y;
  void scan() { cin >> x >> y; }
};
template <typename T>
inline T sqr(const T& a) {
  return a * a;
}
template <typename T>
inline int sign(const T& a) {
  return a < 0 ? -1 : a > 0;
}
void task();
int main() {
  task();
  return 0;
}
int n;
string s;
vector<int> v;
vector<int> cnt(10, 0);
void task() {
  ios_base::sync_with_stdio(0);
  cin >> n;
  cin >> s;
  for (int i = 0; i < s.length(); ++i) v.push_back(s[i] - '0');
  for (int y : v) {
    for (int x = 2; x <= y; ++x) {
      int dd = x;
      for (int d = 2; d <= dd; ++d) {
        while (dd % d == 0) {
          ++cnt[d];
          dd /= d;
        }
      }
    }
  }
  (void(1));
  vector<int> ans;
  for (int i = 9; i > 1; --i) {
    while (cnt[i]) {
      ans.push_back(i);
      cnt[i]--;
      for (int j = i - 1; j > 1; --j) {
        if (j == 2 || j == 3 || j == 5 || j == 7) {
          --cnt[j];
          continue;
        }
        if (j == 6) {
          --cnt[3];
          --cnt[2];
          continue;
        }
        if (j == 4) {
          --cnt[2];
          --cnt[2];
          continue;
        }
      }
    }
  }
  for (int x : ans) cout << x;
}

### Prompt

In Cpp, your task is to solve 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;
template <typename T>
struct Pt {
  T x, y;
  void scan() { cin >> x >> y; }
};
template <typename T>
inline T sqr(const T& a) {
  return a * a;
}
template <typename T>
inline int sign(const T& a) {
  return a < 0 ? -1 : a > 0;
}
void task();
int main() {
  task();
  return 0;
}
int n;
string s;
vector<int> v;
vector<int> cnt(10, 0);
void task() {
  ios_base::sync_with_stdio(0);
  cin >> n;
  cin >> s;
  for (int i = 0; i < s.length(); ++i) v.push_back(s[i] - '0');
  for (int y : v) {
    for (int x = 2; x <= y; ++x) {
      int dd = x;
      for (int d = 2; d <= dd; ++d) {
        while (dd % d == 0) {
          ++cnt[d];
          dd /= d;
        }
      }
    }
  }
  (void(1));
  vector<int> ans;
  for (int i = 9; i > 1; --i) {
    while (cnt[i]) {
      ans.push_back(i);
      cnt[i]--;
      for (int j = i - 1; j > 1; --j) {
        if (j == 2 || j == 3 || j == 5 || j == 7) {
          --cnt[j];
          continue;
        }
        if (j == 6) {
          --cnt[3];
          --cnt[2];
          continue;
        }
        if (j == 4) {
          --cnt[2];
          --cnt[2];
          continue;
        }
      }
    }
  }
  for (int x : ans) cout << x;
}

```