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 PYTHON3):

Solution:
#Bachgold Problem - 749A
n =int(input())
e=0
o=0
z=[]
if (n%2==0):
  while (e<n):
    e=e+2
    z.append(2)
  print(len(z)) 
  for i in z:
    print(i,end="")
    print(" ",end="")
else:
  while (o<n-3):
    o=o+2
    z.append(2)
  z.append(3)
  print(len(z)) 
  for i in z:
    print(i,end="")
    print(" ",end="")