Given the time shown by a wall clock, you have to output the internal angle between the minute and hour hand of the clock.
(Wall Clock displays a 12 hour format.)

For instance, if the time shown is 01:00 , the angle between the hands is 30 degrees.

Input : Time in HH:MM format 
Output: The angle in degrees, correct up to 6 places of decimal.

SAMPLE INPUT
04:00

SAMPLE OUTPUT
120.000000
inp = raw_input().split(':')

H = int(inp[0])
M = int(inp[1])

ang = abs(float((H*30+M*0.5)-(M*6)))

print '%0.6f' % min(360-ang, ang)