A = list(map(int, input().split()))
ans = []
for i in range(1, 10):
	A.append(i)
	c = [0, 0]
	for j in range(1, 10):
		if (tmp := A.count(j)) == 3:
			c[0] += 1
		elif tmp == 2:
			c[1] += 1
	if c == [4, 1]:
		ans.append(i)
	A.pop()
print(len(ans))
print(*ans)