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()
t=input()
cth=sth=ctm=stm=''
for i in range(0,5):
    if i<2:
        cth+=s[i]
        sth+=t[i]
    elif i>2:
        ctm += s[i]
        stm+=t[i]
ah=int(cth)-int(sth)
am=int(ctm)-int(stm)
if ah<0:
    ah=24+ah
if am<0:
    am=60+am
if len(str(ah))==1 and len(str(am))==1:
    print("0",ah,":","0",am,sep='')
elif len(str(ah))==1 and len(str(am))==2:
    print("0",ah,":",am,sep='')
elif len(str(ah))==2 and len(str(am))==1:
    print(ah,":","0",am,sep='')
else:
    print(ah,":",am,sep='')