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(input()); t = list(input())
print(s)
print(t)
h1 = int(s[0]+s[1]); m1 = int(s[3]+s[4]); h2 = int(t[0]+t[1]); m2 = int(t[3]+t[4])
ah = h1-h2
am = m1-m2
if am < 0:
    am += 60
    ah -= 1
if ah < 0:
    ah += 24

if am < 10:
    am = '0'+str(am)
if ah < 10:
    ah = '0'+str(ah)
print(str(ah)+":"+str(am))