package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	n := getNextInt(scanner) + 1
	aa := make([]int, n)
	for i := 0; i < n; i++ {
		aa[n-1-i] = getNextInt(scanner)
	}
	for i := 0; i+3 < n; i++ {
		if aa[i] == 0 {
			continue
		}
		aa[i+2] += aa[i]
		aa[i] = 0
	}
	bb := make([]string, 0)
	for i := first(aa); i < n; i++ {
		bb = append(bb, fmt.Sprintf("%d", aa[i]))
	}
	if len(bb) == 0 {
		fmt.Fprintln(writer, 0)
		fmt.Fprintln(writer, 0)
		return
	}
	fmt.Fprintln(writer, len(bb)-1)
	for i := 0; i < len(bb)/2; i++ {
		bb[i], bb[len(bb)-1-i] = bb[len(bb)-1-i], bb[i]
	}
	fmt.Fprintln(writer, strings.Join(bb, " "))
}

func first(aa []int) int {
	n := len(aa)
	for i := 0; i < n; i++ {
		if aa[i] != 0 {
			return i
		}
	}
	return n
}