a,b = map(int,input().split())
s1 = a*3600 + 60*b
s2 = 60 * b
s_max1 = 12 * 3600
s_max2 = 3600

dig1 = s1/s_max1 * 360
if abs(dig1-360) < 0.01:
    dig1 = 0

dig2 = s2/s_max2 * 360
if abs(dig2-360) < 0.01:
    dig2 = 0

if dig2 > dig1:
    dig1 += 360

if dig2 >= dig1:
    ans = 0
else:
    for i in range(24*3600):

        s1 += 1
        s2 += 1    
        dig1 = s1/s_max1 * 360
        dig2 = s2/s_max2 * 360

        if dig2 == dig1:
            ans = i+1
            break
        elif dig2 > dig1:
            ans = i
            break
    
print(ans)