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:
# Author: Maharshi Gor

def read(t=int):
    return t(input())

def read_arr(t=int):
    return [t(i) for i in str(input()).split()]

t = 1
for i in range(t):
    n = read()
    if n % 2 == 0:
        print(n//2)
        for i in range(n//2):
            print(2,end=' ')
    else:
        print(n//2)
        for i in range((n-2)//2):
            print(2,end=' ')
        print(3)