#include <bits/stdc++.h>
#pragma GCC optimize("Ofast", "O2", "O1", "O3", "unroll-loops", \
                     "omit-frame-pointer", "inline")
#pragma GCC target("avx", "sse4", "sse4.2", "sse3")
#pragma GCC option("arch=native", "tune=native", "no-zero-upper")
using namespace std;
int main() {
  long long n;
  string s;
  cin >> n >> s;
  long long two = 0, three = 0, five = 0, seven = 0;
  for (long long i = 0; i < s.length(); i++) {
    if (s[i] - '0' == 2)
      two++;
    else if (s[i] - '0' == 3)
      three++;
    else if (s[i] - '0' == 4)
      three++, two += 2;
    else if (s[i] - '0' == 5)
      five++;
    else if (s[i] - '0' == 6)
      three++, five++;
    else if (s[i] - '0' == 7)
      seven++;
    else if (s[i] - '0' == 8)
      two += 3, seven++;
    else if (s[i] - '0' == 9)
      seven++, two += 1, three += 2;
  }
  string res = string(seven, '7') + string(five, '5') + string(three, '3') +
               string(two, '2');
  cout << res << endl;
  return 0;
}

### Prompt

Please create a solution in CPP 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("Ofast", "O2", "O1", "O3", "unroll-loops", \
                     "omit-frame-pointer", "inline")
#pragma GCC target("avx", "sse4", "sse4.2", "sse3")
#pragma GCC option("arch=native", "tune=native", "no-zero-upper")
using namespace std;
int main() {
  long long n;
  string s;
  cin >> n >> s;
  long long two = 0, three = 0, five = 0, seven = 0;
  for (long long i = 0; i < s.length(); i++) {
    if (s[i] - '0' == 2)
      two++;
    else if (s[i] - '0' == 3)
      three++;
    else if (s[i] - '0' == 4)
      three++, two += 2;
    else if (s[i] - '0' == 5)
      five++;
    else if (s[i] - '0' == 6)
      three++, five++;
    else if (s[i] - '0' == 7)
      seven++;
    else if (s[i] - '0' == 8)
      two += 3, seven++;
    else if (s[i] - '0' == 9)
      seven++, two += 1, three += 2;
  }
  string res = string(seven, '7') + string(five, '5') + string(three, '3') +
               string(two, '2');
  cout << res << endl;
  return 0;
}

```