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
h,m=raw_input().split(':')
 
i=30*int(h)+int(m)/2.0
j=6*int(m)-i
 
j=abs(j)
 
if j>180:
	ans = 360-j
else:
	ans = j
 
print "%0.6f" %(ans)