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.
wakeupTime = input().split(':')
sleepTime = input().split(':')

wakeHours = int(wakeupTime[0])
sleepHours = int(sleepTime[0])

wakeMin = int(wakeupTime[1])
sleepMin = int(sleepTime[1])

hoursResult = 0
minResult = 0

printedHours = ''
printedMin = ''

if wakeHours < sleepHours or wakeHours == 0:
    wakeHours += 24
    hoursResult = wakeHours - sleepHours
else:
    hoursResult = wakeHours - sleepHours
if wakeMin < sleepMin:
    wakeMin+=60
    minResult = wakeMin - sleepMin
    if hoursResult == 0:
        hoursResult +=24
        hoursResult -=1
else:
    minResult = wakeMin - sleepMin

if hoursResult == 0 or hoursResult == 24:
    printedHours = '00'
elif hoursResult<10:
    printedHours = '0' + str(hoursResult)
else:
    printedHours = str(hoursResult)

if minResult == 0:
    printedMin = '00'
elif minResult<10:
    printedMin = '0' + str(minResult)
else:
    printedMin = str(minResult)

print(printedHours + ':' + printedMin)