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()
vstal=60*(int(s[0])*10+int(s[1]))+10*int(s[3])+int(s[4])
spal=60*(int(t[0])*10+int(t[1]))+10*int(t[3])+int(t[4])
leg=(vstal-spal)%(24*60)


x0=(leg//600)
x1=(leg//60)%10
x2=':'
x3=(leg%60)//10
x4=(leg%60)%10
print(str(x0)+str(x1)+x2+str(x3)+str(x4))


