Problem: Bachgold problem is very easy to formulate. Given a positive integer n represent it as a sum of maximum possible number of prime numbers. One can prove that such representation exists for any integer greater than 1.

Recall that integer k is called prime if it is greater than 1 and has exactly two positive integer divisors — 1 and k. 

Input

The only line of the input contains a single integer n (2 ≤ n ≤ 100 000).

Output

The first line of the output contains a single integer k — maximum possible number of primes in representation.

The second line should contain k primes with their sum equal to n. You can print them in any order. If there are several optimal solution, print any of them.

Examples

Input

5


Output

2
2 3


Input

6


Output

3
2 2 2

Solution (in JAVA):

Solution:
import java.util.*;
import java.io.*;

public class CF749A{ 
  public static int index;
  public static void main(String[] args)throws Exception {
    InputReader in = new InputReader(System.in);
    PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
    int n = in.nextInt();
    
    ArrayList<Integer> list = new ArrayList<Integer>();
    if(n % 2 == 1){
      list.add(3); n -= 3;
    }
    while(n > 0){
      list.add(2);
      n -= 2;
    }
    
    pw.println(list.size());
    for(int i : list) pw.print(i+" ");
    pw.println();
    
    
    pw.close();
  }
  
  static class InputReader {
    public BufferedReader reader;
    public StringTokenizer tokenizer;
    
    public InputReader(InputStream stream) {
      reader = new BufferedReader(new InputStreamReader(stream));
      tokenizer = null;
    }
    
    public String next()throws Exception {
      while (tokenizer == null || !tokenizer.hasMoreTokens())
        tokenizer = new StringTokenizer(reader.readLine());
      return tokenizer.nextToken();
    }
    
    public String nextLine()throws Exception {
      String line = null;
      tokenizer = null;
      line =  reader.readLine();
      return line;
    }
    
    public int nextInt()throws Exception {
      return Integer.parseInt(next());
    }
    
    public double nextDouble() throws Exception{
      return Double.parseDouble(next());
    }
    
    public long nextLong()throws Exception {
      return Long.parseLong(next());
    }
    
  }
}