import math
a, b = map(int, input().split())
if a == 12 and b == 0:
    print(0)
    exit()

if a > 12:
    a -= 12
s = (a/12 + b/60/12)
l = b/60
speed = 1/3600 - 1/3600/12

if l > s:
    r = 1 - (l-s)
else:
    r = s-l

print(math.floor(r/speed))