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 PYTHON):

Solution:
no=input()
no=int(no)
if no !=1:
    n2=no%2
    if n2==0:
        max_no=no/2
        ns=[2]*max_no
    
    elif n2==1:
        max_no=no/2
        ns=[2]*(max_no-1)
        ns.append(3)
    print max_no
    for i in ns:
        print i,