D = int(raw_input())
b = map(int,raw_input().split())
for i in range(D-1):
    b[i+2] += b[i]
    b[i] = 0
for i in [-3,-2,-1]:
    if b[i] != 0 or i == -1:
        print -i-1
        print " ".join(map(str,b[i:]))
        break