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 fileinput import *

for line in input():
    if lineno() == 1:
        wake_up_string = line.strip()
    if lineno() == 2:
        duration_string = line.strip()

wake_up_ints = list(map(int, wake_up_string.split(':')))
duration_ints = list(map(int, duration_string.split(':')))

wake_up_ints[0] += 24
wake_up_ints[1] += 60

sleep_hour = (wake_up_ints[0] - duration_ints[0]) % 24
sleep_min = (wake_up_ints[1] - duration_ints[1]) % 60

print("%02i:%02i" % (sleep_hour, sleep_min))

