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;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long n;
  cin >> n;
  if (!(n & 1)) {
    cout << (n >> 1) << "\n";
    while (n != 0) {
      cout << 2 << " ";
      n -= 2;
    }
  } else {
    vector<long long> v;
    while (n > 3) {
      v.push_back(2);
      n -= 2;
    }
    v.push_back(3);
    cout << v.size() << "\n";
    for (auto i : v) {
      cout << i << " ";
    }
  }
  return 0;
}