import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
from collections import Counter, deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines

D=int(readline())
A=list(map(int,readline().split()))
ans_lst=[0]*3
ans_lst[0]=A[0]
for i in range(1,D+1):
    if i%2==1:
        ans_lst[1]+=A[i]
    else:
        ans_lst[2]+=A[i]
while len(ans_lst)>=2 and ans_lst[-1]==0:
    ans_lst.pop()
print(len(ans_lst)-1)
print(*ans_lst)