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.
s1,s2 = input(),input()
s1h,s1m = map(int,s1.split(":"))
s2h,s2m = map(int,s2.split(":"))
result_in_integer = s1h*60+s1m-s2h*60-s2m
if result_in_integer < 0:
    result_in_integer = 24*60 + result_in_integer
h = str(result_in_integer//60) 
if len(h) == 1:
    h = "0"+h
m = str(result_in_integer%60)
if len(m) == 1:
    m = "0"+m
print(f"{h}:{m}")