# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	A, B = getlist()
	ans = 3
	for i in range(A, B + 1):
		if i in [23, 24, 25]:
			ans -= 1

	print(ans)

if __name__ == '__main__':
	main()