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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
long long fact(long long n) {
  long long ans = 1;
  for (long long i = 2; i <= n; i++) {
    ans = ans * i;
  }
  return ans;
}
long long ncr(long long n, long long r) {
  return fact(n) / (fact(r) * fact(n - r));
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  srand(time(NULL));
  long long n;
  cin >> n;
  if (n % 2 == 0) {
    cout << n / 2 << "\n";
    for (long long i = 1; i <= n / 2; i++) {
      cout << 2 << " ";
    }
  } else {
    cout << (n - 3) / 2 + 1 << "\n";
    for (long long i = 1; i <= (n - 3) / 2; i++) {
      cout << 2 << " ";
    }
    cout << 3;
  }
  return 0;
}