from fractions import Fraction
A, B = map(int, input().split())
h = Fraction((A*60*60+B*60)%(12*60*60), 12*60*60)
m = Fraction(B*60, 60*60)
if m<=h:
    flag = True
else:
    flag = False
for i in range(120*60):
    if flag and h==m:
        print(i)
        exit()
    elif flag and h<m:
        print(i-1)
        exit()
    elif m<=h:
        flag = True
    h += Fraction(1, 12*60*60)
    if h>=1:
        h-=1
    m += Fraction(1, 60*60)
    if m>=1:
        m-=1