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()
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))
