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.io.*;
import java.util.Scanner;
import java.util.Arrays;
import java.lang.Math;
import java.math.BigInteger;
import java.math.BigDecimal;
import java.util.Collections;
import java.util.HashMap;
public class bachgold{
    public static void main(String[] args){
      Scanner sc= new Scanner(System.in); 
      //int t=sc.nextInt();
      //for(int j=0;j<t;j++){
         int n=sc.nextInt();
         if(n%2==0){
            System.out.println(n/2);
            for(int i=0;i<n/2;i++){
               System.out.print(2+" ");
            }
         }
         else{
            System.out.println(n/2);
            for(int i=1;i<n/2;i++){
               System.out.print(2+" ");  
            }
            System.out.println(3);
         }
      
   }       
}