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.
s = input()
t = input()

import datetime

sTime = datetime.datetime.strptime(s, '%H:%M')
tTime = datetime.datetime.strptime(t, '%H:%M')

x = sTime - tTime

days, seconds = x.days, x.seconds
hours = seconds // 3600
minutes = (seconds % 3600) // 60

strmin = str(minutes)
strhour = str(hours)

if minutes < 10 : strmin = '0'+strmin
if hours < 10 : strhour = '0'+strhour
print(strhour + ":" + strmin)

