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

# Calculate the angles of the hour and minute hands
hour_angle = A * 30 + B * 0.5
minute_angle = B * 6

# Compute the difference modulo 360
diff = (hour_angle - minute_angle) % 360

# Check if the difference is effectively zero considering floating-point precision
epsilon = 1e-10
if diff < epsilon or (360 - diff) < epsilon:
    print(0)
else:
    # Convert the difference to seconds
    x = int(diff * 2)  # diff is a multiple of 0.5, so x is an integer
    seconds = (x * 60) // 11
    print(seconds)