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.
h1,m1=list(map(int,input().split(":")))
h2,m2=list(map(int,input().split(":")))
if m1<m2:
    m1=m1+1
    h1=h1-1
    t=m1-m2
    if h1<h2:
        h1=h1+24
        p=h1-h2
        if t<10:
            t="0"+str(t)
        if p<10:
            p="0"+str(p)
        print("{}:{}".format(p,t))
    else:
        p=h1-h2
        if t<10:
            t="0"+str(t)
        if p<10:
            p="0"+str(p)
        print("{}:{}".format(p,t))
else:
    t=m1-m2
    if h1<h2:
        h1=h1+24
        p=h1-h2
        if t<10:
            t="0"+str(t)
        if p<10:
            p="0"+str(p)
        print("{}:{}".format(p,t))
    else:
        p=h1-h2
        if t<10:
            t="0"+str(t)
        if p<10:
            p="0"+str(p)
        print("{}:{}".format(p,t))
