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.
a=input()
b=input()
z=int(a[:2])
z2=int(b[:2])
z=z-z2
if z<0:
    z=24+z
else:
    z=str(z)
    if len(z)==1:
        z='0'+z
hs=z
z=int(a[3:])
z2=int(b[3:])
z=z-z2
if z>=0:
    z=str(z)
    if len(z)==1:
        z='0'+z
else:
    z=60+z
    hs=int(hs)
    i=hs-1
    if i<0:
        i=24+i
    else:
        i=str(i)
        if len(i)==1:
            i='0'+i
    hs=i
hs=str(hs)
z=str(z)
print(hs+':'+z)
