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()
ss=list(map(int,s.split(":")))
tt=list(map(int,t.split(":")))
res=[0,0]
res[1]=ss[1]-tt[1]
res[0]=ss[0]-tt[0]
if res[1]<0:
	res[0]-=1
	res[1]+=60
if res[0]<0:
	res[0]+=26

fin=""
if res[0]<10:
	fin+="0"+str(res[0])
else:
	fin+=str(res[0])
fin+=":"
if res[1]<10:
	fin+="0"+str(res[1])
else:
	fin+=str(res[1])
print(fin)