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=map(int,input().split(':'))
h2,m2=map(int,input().split(':'))
if h1<h2 or (h1==h2 and m1<m2):
    h1+=23
    m1+=60
    h3=h1-h2
    m3=m1-m2
else:
    if m1<m2:
        h1-=1
        m1+=60
        h3=h1-h2
        m3=m1-m2
    else:
        h3=h1-h2
        m3=m1-m2
if m3==60:
    h3+=1
    m3=0
if h3==24:
    h3=0
if h3<10:
    h3='0'+str(h3)
if m3<10:
    m3='0'+str(m3)
print('{}:{}'.format(h3,m3))
