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.
time1 = input().split(':')
time2 = input().split(':')

if len(str((int(time1[0]) - int(time2[0])) % 24)) <= 1 and len(str((int(time1[1]) - int(time2[1])) % 60)) <= 1:
    print('0' + str((int(time1[0]) - int(time2[0])) % 24) + ':' + '0' + str((int(time1[1]) - int(time2[1])) % 60))
elif len(str((int(time1[0]) - int(time2[0])) % 24)) <= 1:
    print('0' + str((int(time1[0]) - int(time2[0])) % 24) + ':' + str((int(time1[1]) - int(time2[1])) % 60))
elif len(str((int(time1[1]) - int(time2[1])) % 60)) <= 1:
    print(str((int(time1[0]) - int(time2[0])) % 24) + ':' + '0' +  str((int(time1[1]) - int(time2[1])) % 60))    
else:
    print(str((int(time1[0]) - int(time2[0])) % 24) + ':' + str((int(time1[1]) - int(time2[1])) % 60))