import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int k = sc.nextInt();
        int[] counts = new int[k + 1];
        int[] lefts = new int[k + 1];
        int[] rights = new int[k + 1];
        for (int i = 1; i <= k; i++) {
            for (int j = 1; j <= Math.sqrt(i); j++) {
                if (i % j == 0) {
                    counts[i] = j + i / j;
                    lefts[i] = j;
                    rights[i] = i / j;
                }
            }
        }
        ArrayList<Integer> ans = new ArrayList<>();
        for (int i = 0; i <= k / 2; i++) {
            if (counts[i] + counts[k - i] <= 250) {
                for (int j = 0; j < lefts[i]; j++) {
                    ans.add(3);
                }
                for (int j = 0; j < rights[i]; j++) {
                    ans.add(4);
                }
                for (int j = 0; j < lefts[k - i]; j++) {
                    ans.add(5);
                }
                for (int j = 0; j < rights[k - i]; j++) {
                    ans.add(6);
                }
                break;
            }
        }
        System.out.println(ans.size());
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < ans.size(); i++) {
            if (i > 0) {
                sb.append(" ");
            }
            sb.append(ans.get(i));
        }
        System.out.println(sb);
    }
}

class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}