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=input()
b=input()
c=a.split(":")
d=b.split(":")
currenttime1=int (c[0])
if int(c[0][0])==0 :
    currenttime1=int(c[0][1])      
currenttime2= int (c[1])
if int(c[-1][0])==0 :
    currenttime2=int(c[1][1])  
duration1=int(d[0])
if int(c[0][0])==0 :
    duration1=int(d[0][1])  
duration2=int(d[1])
if int(c[-1][0])==0 :
    duration=int(d[1][1]) 
time =currenttime1-duration1
if currenttime1<duration1:
    time = 24 - duration1
time2 = currenttime2-duration2 
if currenttime2<duration2:
    time2= 60 - duration2 
    if time == 0 :
       time= 24 - 1
    else: 
       time= time -1
if time <=9 : 
   time='0'+ str(time)
if time2 <=9 : 
   time2='0'+ str(time2)
print(str(time)+':'+str(time2))


 	 	 	 		  	  	 	 					 	 	