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.
h, m = map(int, input().split(":"))
hh, mm = map(int, input().split(":"))

h = h* 60       
hh = hh * 60
m += h
mm += hh
ot = m - mm
if ot<0:
    ot = 24*60 - abs(ot)
otm = str(ot % 60)
oth = str(ot // 60)
if len(oth) == 1:
    oth = "0" + oth
if len(otm) == 1:
    otm = "0" + otm
print(oth+":"+otm)    