George woke up and saw the current time *s* on the digital clock. Besides, George knows that he has slept for time *t*. 

Help George! Write a program that will, given time *s* and *t*, determine the time *p* when George went to bed. Note that George could have gone to bed yesterday relatively to the current time (see the second test sample).
The first line contains current time *s* as a string in the format "hh:mm". The second line contains time *t* in the format "hh:mm" — the duration of George's sleep. It is guaranteed that the input contains the correct time in the 24-hour format, that is, 00 ≤ *hh* ≤ 23, 00 ≤ *mm* ≤ 59.
(current_time_hour, current_time_minute) = map(str, input().split(':'))
(duration_of_sleep_hours, duration_of_sleep_minutes) = map(str, input().split(':'))

slept_hours = 0
slept_minutes = 0

if int(current_time_hour) >= int(duration_of_sleep_hours):
    slept_hours = str(int(current_time_hour) - int(duration_of_sleep_hours))
else:
    slept_hours = str(24 + int(current_time_hour) - int(duration_of_sleep_hours))

if int(current_time_minute) >= int(current_time_minute):
    slept_minutes = str(int(current_time_minute) - int(duration_of_sleep_minutes))
else:
    slept_minutes = str(60 + int(current_time_minute) - int(duration_of_sleep_minutes))
    slept_hours -= 1

if len(slept_hours) == 1:
    slept_hours = '0' + slept_hours
if len(slept_minutes) == 1:
    slept_minutes = '0' + slept_minutes

print(slept_hours + ':' + slept_minutes)


