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.
ch,m=input().split(":")
tch,tm=input().split(":")

ch=int(ch)
tch=int(tch)
m=int(m)
tm=int(tm)

s1=ch*60+m
s2=tch*60+tm

s3=s1-s2

if s3<0:
    s3=24*60+s3

ch=s3//60
m=s3%60

if(ch<10):
    print("0"+str(ch),end=":")
else:
    print(str(ch),end=":")

if(m<10):
    print("0"+str(m))
else:
    print(str(m))