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.
s1=input().strip()
s2=input().strip()
h1=int(s1[:2])
h2=int(s2[:2])
m1=int(s1[3:])
m2=int(s2[3:])
h3=h1-h2
m3=m1-m2
if m3<0:
    m3=60+m3
    h3-=1
if h3<0:
    h3=24+h3
print((2-len(str(h3)))*'0'+str(h3)+':'+(2-len(str(m3)))*'0'+str(m3))
