#多項式の割り算

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

ans = 0
ans_text = str(a[0])
if D < 3:
    ans = D
else:
    for i in range(D , 2 , -1):
        a[i - 2] += a[i]
        a[i] = 0
    ans = 2
    for j in range(2 , 0 , -1):
        if a[j] == 0:
            ans -= 1
        else:
            break

for k in range(1 , ans + 1):
    ans_text += " " + str(a[k])

print(ans)
print(ans_text)