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.
from datetime import datetime, date, time, timedelta

def hours_minutes(td):
    return td.seconds//3600, (td.seconds//60)%60

strdtupper = input().split(':')
strdtsleep = input().split(':')

dtup = time(int(strdtupper[0]),int(strdtupper[1]))
dtsleep = time(int(strdtsleep[0]),int(strdtsleep[1]))

answerdate = timedelta(minutes = dtup.minute, hours = dtup.hour) - timedelta(minutes = dtsleep.minute, hours = dtsleep.hour)

dateZ = hours_minutes(answerdate)

print('{}:{}'.format((lambda x:'0{}'.format(x) if x//10 <= 0 else x)(dateZ[0]),(lambda x:'0{}'.format(x) if x//10 <= 0 else x)(dateZ[1])))