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.
x=input()
x=x.replace(':'," ")
x=x.split()
y=input()
y=y.replace(':'," ")
y=y.split()

if ( x[0] == y[0] and int(x[1]) < int(y[1]) ):
      print( str(24-(int(y[0])-int(x[0]))-1)+":"+str(60-(int(y[1])-int(x[1]))))
else :
      a=int(x[0])-int(y[0])
      b=int(x[1])-int(y[1])
      if a < 0 :
            a=24+a
      if b >= 60 :
            a=a-1
            b=b-60
      f=0
      while f < 10 :
            if a == f :
                  a='0'+str(a)
            if b == f :
                  b='0'+str(b)
            f=f+1
      print(str(a)+":"+str(b))
