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=input()

wh=int(s[0]+s[1])
wm=int(s[3]+s[4])

s=input()

th=int(s[0]+s[1])
tm=int(s[3]+s[4])

tm+=th*60

wm+=wh*60

wm-=tm
if(wm<0):
    wm=1440+wm
ansh=str(wm//60)
ansm=str(wm%60)
if(len(ansh)<2):
    ansh='0'+ansh
if(len(ansm)<2):
    ansm='0'+ansm
print(ansh+":"+ansm)
