import java.util.*;

public class Yukicoder_40{
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		int D = stdIn.nextInt();
		int[] b = new int[D+1];
		for(int i=0;i<D+1;i++){
			b[i] = stdIn.nextInt();
		}

		for(int i=D;i>=3;i--){
			b[i-2] = b[i-2] + b[i];
			b[i] = 0;
		}

		for(int i=2;i>=0;i--){
			if(b[i] != 0){
				System.out.println(i);
				for(int j=0;j<=i;j++){
					if(j==i){
						System.out.println(b[j]);
						break;
					}
					System.out.print(b[j]+" ");
				}
				break;
			}
			if(i==0){
				System.out.println(i+"\n"+i);
			}
		}

	}
}