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.
t = input()
T = t.split(":")
HT = int(T[0])
MT = int(T[1])
s = input()
S = s.split(":")
HS = int(S[0])
MS = int(S[1])
MR = MT - MS
if(MR<0):
    MR+=60
    HT-=1
HR = HT - HS
if(HR<0):
    HR+=24
if(HR<10):
    h="0"+str(HR)
else:
    h=str(HR)
if(MR<10):
    m="0"+str(MR)
else:
    m=str(MR)
print(h+":"+m)