A = list(map(int, input().split()))
cnt = [0] * 10
for i in A: cnt[i] += 1
cnt_d = [[] for _ in range(4)]
for i in range(1, 10):
	if cnt[i] <= 3:
		cnt_d[cnt[i]].append(i)
if len(cnt_d[3]) == 4:
	print(1)
	print(cnt_d[1][0])
elif len(cnt_d[3]) == 3 and len(cnt_d[2]) == 2:
	print(2)
	print(*cnt_d[2])
else:
	print(0)
	print()