def bit(val, n):
	return (val >> n) & 1

def tdms_encode(data):
	ones = 0
	for i in range(0, 8):
		if bit(data, i):
			ones += 1

	if ones > 4 or (ones == 4 and ((data & 1) == 0)):
		b8 = 0
		nb8 = 1
	else:
		b8 = 1
		nb8 = 0

	result = data & 1
	for i in range(1, 8):
		result |= (bit(result, i - 1) ^ bit(data, i) ^ nb8)  << i

	return result | (b8 << 8)


def count_transistions(val):
	count = 0
	for i in range(1,9):
		if bit(val, i - 1) != bit(val, i):
			count += 1
	return count

max_transitions = 0

for i in range(0,256):
	data = tdms_encode(i)
	x = count_transistions(data)
	if x > max_transitions:
		max_transitions = x
#	print(i, bin(x), x)

print max_transitions