d = int(input())
a = list(map(int,input().split()))

if d < 3:
	print(d)
	print(" ".join(map(str,a)))
else:
	for i in range(d + 1):
		if a[d - i] != 0:
			n = d - i
			if n < 3:
				break
			a[n - 2] += a[n]
			a[n] = 0

	for i in range(3):
		if a[2 - i] != 0:
			dd = 2 - i
			a = a[:dd + 1]
			break
		if 2 - i == 0:
			dd = 0
			a = [0]

	print(dd)
	print(" ".join(map(str,a)))