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 JAVA):

Solution:
import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws FileNotFoundException, IOException {
        InputStream inputStream = System.in;
//        InputStream inputStream = new FileInputStream("dijkstra.in");
        OutputStream outputStream = System.out;
//        OutputStream outputStream = new FileOutputStream("dijkstra.out");
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Answer solver = new Answer();
        solver.solve(1, in, out);
        out.close();
    }

    static class Answer {
        public void solve(int testNumber, InputReader in, PrintWriter out) throws IOException {
            int n = in.nextInt();
            List<Integer> ans = new ArrayList<>();
            for (int i = 0; i < n >> 1; i++) {
                ans.add(2);
            }

            if (n % 2 == 1) {
                ans.set(ans.size() - 1, 3);
            }

            out.println(ans.size());
            for (Integer x : ans) {
                out.print(x + " ");
            }
            out.println();
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }
    }
}