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

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

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

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

v = vb - va
ans = 1 * (d / v)
#print(f'{d=} {v=}')
print(int(ans))