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:
number = int(input())
r_data = []
result = 0
while number >= 2:
    if number == 2:
        number -= 2
        r_data.append(2)
        result += 1
    elif number == 3:
        number -= 3
        r_data.append(3)
        result += 1
    else:
        number -= 2
        r_data.append(2)
        result += 1
print(result)
for m in r_data:
    print(m, end=" ")