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.
now_h, now_m = map(int, input().split(":"))
sleep_h, sleep_m = map(int, input().split(":"))

borrow = False
if now_m >= sleep_m:
    result_m = now_m - sleep_m
else:
    result_m = 60 - (sleep_m-now_m)
    borrow = True

if borrow:
    now_h -= 1
if now_h >= sleep_h:
    result_h = now_h - sleep_h
else:
    result_h = 24 - (sleep_h-now_h)
while result_h < 0:
    result_h += 24


result_h = str(result_h)
result_m = str(result_m)

if len(result_h) == 1:
    result_h = "0"+result_h
if len(result_m) == 1:
    result_m = "0"+result_m

print(f"{result_h}:{result_m}")
