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 = list(map(int, input().split(':')))
t = list(map(int, input().split(':')))

time_to_bed = [s[0] - t[0], s[1] - t[1]]

if time_to_bed[1] < 0:
	time_to_bed[1] += 60
	time_to_bed[0] += -1

if time_to_bed[0] < 0:
	time_to_bed[0] += 24

if time_to_bed[0] // 10 == 0:
	time_to_bed[0] = '0' + str(time_to_bed[0])
if time_to_bed[1] // 10 == 0:
	time_to_bed[1] = '0' + str(time_to_bed[1])

print(*time_to_bed, sep = ':')
