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.
def george_sleep(a,b):
    # a=list(a)
    # b=list(b)
    # for i in range(len(a)):
    m1=int(a[3:])
    m2=int(b[3:])
    h1=int(a[0:2])
    h2=int(b[0:2])

    total1=h1*60+m1
    total2=h2*60+m2

    total=total1-total2

    if total>=0:
        h=total//60
        if h==24:
            h=23
        m=total%60
        if m==60:
            m=0
    else:
        h=24-abs(total)//60
        if h==24:
            h=23
        m=60-abs(total)%60
        if m==60:
            m=0
    
    h=str(h)
    m=str(m)

    if len(h)==1:
        h='0'+h
        
    print(h,end='')
    
    print(':',end='')
    
    if len(m)==1:
        m='0'+m
    print(m)




a=input('')
b=input('')
george_sleep(a,b)