#include <bits/stdc++.h>
using namespace std;
template <class A, class B>
ostream& operator<<(ostream& o, const pair<A, B>& p) {
  return o << "(" << p.first << ", " << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& o, const vector<T>& v) {
  o << "[";
  for (__typeof((v).end()) it = (v).begin(); it != (v).end(); ++it)
    o << *it << ", ";
  return o << "]";
}
template <class T>
ostream& operator<<(ostream& o, const set<T>& v) {
  o << "[";
  for (__typeof((v).end()) it = (v).begin(); it != (v).end(); ++it)
    o << *it << ", ";
  return o << "]";
}
template <class T>
inline void MAX(T& a, T b) {
  if (a < b) a = b;
}
template <class T>
inline void MIN(T& a, T b) {
  if (a > b) a = b;
}
template <class T>
inline bool read(T& x) {
  int c = getchar();
  int sgn = 1;
  while (~c && c < '0' || c > '9') {
    if (c == '-') sgn = -1;
    c = getchar();
  }
  for (x = 0; ~c && '0' <= c && c <= '9'; c = getchar()) x = x * 10 + c - '0';
  x *= sgn;
  return ~c;
}
int main() {
  int n;
  cin >> n;
  string num;
  cin >> num;
  vector<int> ans, temp;
  for (int i = 0; i < num.length(); i++) {
    int a = num[i] - '0';
    if (a <= 1) {
      continue;
    } else {
      temp.push_back(a);
    }
  }
  sort(temp.begin(), temp.end());
  for (int i = 0; i < (int)temp.size(); i++) {
    if (temp[i] == 2 || temp[i] == 3 || temp[i] == 5 || temp[i] == 7) {
      ans.push_back(temp[i]);
    } else {
      if (temp[i] == 9) {
        ans.push_back(7);
        ans.push_back(3);
        ans.push_back(3);
        ans.push_back(2);
        continue;
      }
      ans.push_back(temp[i] - 1);
      if (temp[i] == 6) {
        ans.push_back(3);
      } else if (temp[i] == 4) {
        ans.push_back(2);
        ans.push_back(2);
      } else if (temp[i] == 8) {
        ans.push_back(2);
        ans.push_back(2);
        ans.push_back(2);
      }
    }
  }
  sort(ans.begin(), ans.end(), greater<int>());
  for (int i = 0; i < (int)ans.size(); i++) {
    cout << ans[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;
template <class A, class B>
ostream& operator<<(ostream& o, const pair<A, B>& p) {
  return o << "(" << p.first << ", " << p.second << ")";
}
template <class T>
ostream& operator<<(ostream& o, const vector<T>& v) {
  o << "[";
  for (__typeof((v).end()) it = (v).begin(); it != (v).end(); ++it)
    o << *it << ", ";
  return o << "]";
}
template <class T>
ostream& operator<<(ostream& o, const set<T>& v) {
  o << "[";
  for (__typeof((v).end()) it = (v).begin(); it != (v).end(); ++it)
    o << *it << ", ";
  return o << "]";
}
template <class T>
inline void MAX(T& a, T b) {
  if (a < b) a = b;
}
template <class T>
inline void MIN(T& a, T b) {
  if (a > b) a = b;
}
template <class T>
inline bool read(T& x) {
  int c = getchar();
  int sgn = 1;
  while (~c && c < '0' || c > '9') {
    if (c == '-') sgn = -1;
    c = getchar();
  }
  for (x = 0; ~c && '0' <= c && c <= '9'; c = getchar()) x = x * 10 + c - '0';
  x *= sgn;
  return ~c;
}
int main() {
  int n;
  cin >> n;
  string num;
  cin >> num;
  vector<int> ans, temp;
  for (int i = 0; i < num.length(); i++) {
    int a = num[i] - '0';
    if (a <= 1) {
      continue;
    } else {
      temp.push_back(a);
    }
  }
  sort(temp.begin(), temp.end());
  for (int i = 0; i < (int)temp.size(); i++) {
    if (temp[i] == 2 || temp[i] == 3 || temp[i] == 5 || temp[i] == 7) {
      ans.push_back(temp[i]);
    } else {
      if (temp[i] == 9) {
        ans.push_back(7);
        ans.push_back(3);
        ans.push_back(3);
        ans.push_back(2);
        continue;
      }
      ans.push_back(temp[i] - 1);
      if (temp[i] == 6) {
        ans.push_back(3);
      } else if (temp[i] == 4) {
        ans.push_back(2);
        ans.push_back(2);
      } else if (temp[i] == 8) {
        ans.push_back(2);
        ans.push_back(2);
        ans.push_back(2);
      }
    }
  }
  sort(ans.begin(), ans.end(), greater<int>());
  for (int i = 0; i < (int)ans.size(); i++) {
    cout << ans[i];
  }
}

```