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.
finish = str(input())
distance = str(input())

def get_minutes(time):
    h, m = time.split(':')
    h = int(h)
    m = int(m)
    result = h * 60 + m
    return result

def get_clock(minutes):
    h = minutes // 60
    m = minutes - (60 * h)
    return (h, m)

finish = get_minutes(finish)
distance = get_minutes(distance)

result_minutes = finish - distance
if result_minutes < 0:
    result_minutes = (24 * 60) + result_minutes

h, m = get_clock(result_minutes)
result = ''
if len(str(h)) == 1:
    result = f'0{h}:'
else:
    result = f'{h}:'

if len(str(m)) == 1:
    result = result + f'0{m}'
else:
    result = result + f'{m}'

print(result)
