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.
a,b=map(int,input().split(":"))
c,d=map(int,input().split(":"))
e=a*60+b
f=c*60+d
j=e-f
if(j<0):
    j=24*60+j
j1=str(j//60)
j2=str(j%60)
if(len(j1)==1):
    j1="0"+j1
if(len(j2)==1):
    j2="0"+j2
res=j1+":"+j2
print(res)