first = input()
first_data = first.split(" ")

from_d = int(first_data[0])
to_d = int(first_data[1])+1

result = 3

for number in range(from_d,to_d):
	if number == 23:
		result = result -1

	if number == 24:
		result = result -1

	if number == 25:
		result = result -1

print(result)