#!/usr/bin/python

def sub(a,b):
	m=max(len(a),len(b))
	return [(0 if len(a)<=i else a[i])+(0 if len(b)<=i else -b[i]) for i in range(m)]

def checkio(exp,div):
	c=[]
	while len(div)<=len(exp):
		d=exp[-1]//div[-1]
		c.append(d)
		exp=sub(exp,[0]*(len(exp)-len(div))+[e*d for e in div])
		#assert exp[-1]==0
		exp.pop()
	while len(exp)>1 and exp[-1]==0: exp.pop()
	print(len(exp)-1)
	print(' '.join(str(e) for e in exp))

import sys
if sys.version_info[0]>=3: raw_input=input
raw_input()
checkio([int(e) for e in raw_input().split()],[0,-1,0,1])