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:
a=int(input())
i=1
lst=[]
v=' '
if(a%2==0):
    k=a//2
    print(k)
    while(i<=k):
        lst.append('2')
        i=i+1
    for u in lst:
        print(u,end=' ')
else:
    t=a//2
    k=t-1
    print(k+1)
    while(i<=k):
        lst.append('2')
        i=i+1
    for u in lst:
        r=str(u)
        v=v+' '+r
    print(v[2::]+' '+'3')