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

def f(x):
	ret = 0
	for i in xrange(D + 1):
		ret += a[i] * x ** i
	return ret

x = (f(1) + f(-1) - 2 * f(0)) / 2
y = (f(1) - f(-1)) / 2
z = f(0)

if x != 0:
	print 2
	print z, y, x
elif y != 0:
	print 1
	print z, y
else:
	print 0
	print z