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=list(map(lambda x:int(x),input().split(':')))
s=list(map(lambda x:int(x),input().split(':')))
if t[0]==0:
    t[0]=24
if s[0]>=24:
    s[0]=s[0]-24
if t[1]<s[1]:
    t[0]=t[0]-1
    t[1]=t[1]+60
if t[0]-s[0]<10:
    res1='0'+str(t[0]-s[0])
else:
    res1=str(t[0]-s[0])
if t[1]-s[1]<10:
    res2='0'+str(t[1]-s[1])
else:
    res2=str(t[1]-s[1])
if res1=='24':
    res1='00'
print(res1+':'+res2)