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.
s1=input()
s2=input()
wakehours=int(s1[:2])
wake_min=int(s1[3:])
sleephours=int(s2[:2])
sleep_min=int(s2[3:])
time_hours=wakehours
time_min=wake_min
if sleep_min>wake_min:
    wake_min+=60
    wakehours-=1
time_min=(wake_min-sleep_min)
if sleephours>wakehours:
    wakehours+=24

time_hours=wakehours-sleephours
if time_hours<10 and time_min<10:
    
    print("0"+str(time_hours)+":0"+str(time_min))
elif time_hours<10:
    print("0"str(time_hours)+":"+str(time_min))
elif time_min<10:
    print(str(time_hours)+":0"+str(time_min))
else:
    print(str(time_hours)+":"+str(time_min))
    
    
    
    
        
    
    




        
            
        
            
    
    
            
    
        

    
