#include <bits/stdc++.h>
using namespace std;
int mod = 1000000007;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
inline long long toll(string s) {
  long long v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T>
inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
int dcmp(double x, double y) {
  return fabs(x - y) <= 1e-9 ? 0 : x < y ? -1 : 1;
}
void printV(vector<int> v) {
  for (int i = 0; i < v.size(); i++) {
    if (i) {
      cout << " " << v[i];
    } else
      cout << v[i];
  }
}
int fixMod(int a) { return (a % mod + mod) % mod; }
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  map<char, string> ma;
  ma['0'] = "";
  ma['1'] = "";
  ma['2'] = "2";
  ma['3'] = "3";
  ma['4'] = "223";
  ma['5'] = "5";
  ma['6'] = "35";
  ma['7'] = "7";
  ma['8'] = "2227";
  ma['9'] = "2337";
  int n;
  cin >> n;
  string s;
  cin >> s;
  string res = "";
  for (int i = 0; i < n; i++) {
    res += ma[s[i]];
  }
  sort(res.rbegin(), res.rend());
  cout << res << endl;
  ;
  return 0;
}

### 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;
int mod = 1000000007;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
inline long long toll(string s) {
  long long v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T>
inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
int dcmp(double x, double y) {
  return fabs(x - y) <= 1e-9 ? 0 : x < y ? -1 : 1;
}
void printV(vector<int> v) {
  for (int i = 0; i < v.size(); i++) {
    if (i) {
      cout << " " << v[i];
    } else
      cout << v[i];
  }
}
int fixMod(int a) { return (a % mod + mod) % mod; }
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  map<char, string> ma;
  ma['0'] = "";
  ma['1'] = "";
  ma['2'] = "2";
  ma['3'] = "3";
  ma['4'] = "223";
  ma['5'] = "5";
  ma['6'] = "35";
  ma['7'] = "7";
  ma['8'] = "2227";
  ma['9'] = "2337";
  int n;
  cin >> n;
  string s;
  cin >> s;
  string res = "";
  for (int i = 0; i < n; i++) {
    res += ma[s[i]];
  }
  sort(res.rbegin(), res.rend());
  cout << res << endl;
  ;
  return 0;
}

```