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()
h0=int(s[:2])
h1=int(t[:2])
m0=int(s[3:])
m1=int(t[3:])
hp=h0-h1
mp=m0-m1
if mp<0:
    mp+=60
    hp-=1
if hp<0:
    hp+=24
print("%02d:%02d" % (hp,mp))
