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:
n = int(input())
if(n % 2 == 0):
    a = 2
    b = 1
    li = [2]
    while(a < n):
        li.append(2)
        a = a + 2
        b = b + 1
    print(b)
    for i in range(0,len(li)-1):
        print(li[i],end=" ")
    print(li[-1])
if(n % 2 == 1):
    a = 3
    b = 1
    li = [3]
    while(a < n):
        li.append(2)
        a = a + 2
        b = b + 1
    print(b)
    for i in range(0,len(li)-1):
        print(li[i],end=" ")
    print(li[-1])