A, B = map(int, input().split())
A = A % 12

K = 120

# 短針
va = K * (1 / 120)
# 長針
vb = K * (1 / 10)

pa = K * 30 * A + K * B / 2
pb = K * 6 * B

if pa >= pb:
    d = pa - pb
else:
    d = K * 360 - abs(pb - pa)

v = vb - va
ans = d / v
print(int(ans))