import itertools as it

d = int(input())
a_list = list(map(int, input().split()))
a_list.reverse()

for i in range(len(a_list) - 3):
    a_list[i+2] += a_list[i]

result = list(it.dropwhile(lambda x: x == 0, a_list[-3:]))

result.reverse()
if len(result) == 0:
    print(0)
    print(0)
else:
    print(len(result) - 1)
    print(" ".join(map(str, result)))