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 = input()
time_duration = input()

current_time_min = int(current_time[:2]) * 60 + int(current_time[3:])
time_duration_min = int(time_duration[:2]) * 60 + int(time_duration[3:])
t_min = current_time_min - time_duration_min

if current_time_min < time_duration_min:
    t_min = 24 * 60 - abs(t_min)

hour = "0" + str(t_min // 60) if t_min // 60 < 10 else str(t_min // 60)
minute = "0" + str(t_min % 60) if t_min % 60 < 10 else str(t_min % 60)
print(f"{hour}:{minute}")
