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

    a.reverse()
    for i in range(d-2):
        a[i+2] += a[i]
        a[i] = 0

    i = 0
    while i <= d and not a[i]:
        i += 1

    if i == d + 1:
        print("0\n0")
    else:
        print(d-i)
        for j in range(d, i-1, -1):
            print(a[j], end=" ")
        print()


if __name__ == '__main__':
    main()