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.
q = input()
w= input()
q = q.split(":")
w=  w.split(":")

a=int(q[0])
b=int(w[0])
aa=int(q[1])
bb=int(w[1])

if aa<bb:
    aa=aa+60
    a=a-1

rr= aa-bb

if a<b:
    a=a+24

gg = a-b
if gg <10:
    gg = "0"+str(gg)
if rr <10:
    rr = "0"+str(rr)



print(str(gg)+":"+str(rr))
    