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.
# LUOGU_RID: 92903906
time_1 = input().split(":")
time_2 = input().split(":")
a1, b1 = int(time_1[0]), int(time_1[1])
a2, b2 = int(time_2[0]), int(time_2[1])
if b1 < b2:
    a1 -= 1
    b1 += 60
elif a1 < a2:
    a1 += 24
a3 = a1 - a2
b3 = b1 - b2
print("{:02}:{:02}".format(a3, b3))
