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.
s_hour, s_minute = map(int, input().split(":"))
t_hour, t_minute = map(int, input().split(":"))

if s_minute < t_minute:
    s_minute = 60 + s_minute - t_minute
    if s_hour == 0:
        s_hour = 23
    else:
        s_hour -= 1
else:
    s_minute -= t_minute

if s_hour < t_hour:
    s_hour = 24 + s_hour - t_hour

else:
    s_hour -= t_hour

time =(2 - len(str(s_hour)))*"0" + str(s_hour) + ":" + (2 - len(str(s_minute)))*"0" + str(s_minute)
print(time)
