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.
woke_up = input()
sleep_for = input()
hours = int(sleep_for[0: 2])
minutes = int(sleep_for[3:])
woke_up_hr = int(woke_up[0: 2])
woke_up_min = int(woke_up[3:])
# Reduce the hours
if woke_up_hr - hours >= 0:
    sleep_time_hr = woke_up_hr - hours
else:
    sleep_time_hr = 24 + woke_up_hr - hours
# Reduce the minutes
if woke_up_min - minutes >= 0:
    sleep_time_min = woke_up_min - minutes
else:
    sleep_time_min = 60 + woke_up_min - minutes
    if sleep_time_hr > 0:
        sleep_time_min -= 1
    else:
        sleep_time_hr = 23
# print(sleep_time_hr)
# print(sleep_time_min)
final_format = ""
if sleep_time_hr < 10:
    final_format += "0"
final_format += str(sleep_time_hr)
final_format += ":"
if sleep_time_min < 10:
    final_format += "0"
final_format += str(sleep_time_min)
print(final_format)
