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.
time = input()
duration = input()

time_hour = time[0:2]
time_minute = time[-2:]
duration_hour = duration[0:2]
duration_minute = duration[-2:]

if (time_hour[0] == 0):
    time_hour.pop(0)

if (time_minute[0] == 0):
    time_minute.pop(0)

if (duration_hour[0] == 0):
    duration_hour.pop(0)

if (duration_minute[0] == 0):
    duration_minute.pop(0)

g2b_hour = int(time_hour) - int(duration_hour)
g2b_hour = str(g2b_hour)
if int(g2b_hour) < 0:
    g2b_hour = int(g2b_hour)
    g2b_hour += 24
    g2b_hour = str(g2b_hour)
if 0 <= int(g2b_hour) < 10:
    g2b_hour = list(str(g2b_hour))
    g2b_hour.insert(0,"0")
    g2b_hour = "".join(g2b_hour)

g2b_minute = int(time_minute) - int(duration_minute)
g2b_minute = str(g2b_minute)
if int(g2b_minute) < 0:
    g2b_minute = int(g2b_minute)
    g2b_minute += 60
    g2b_hour = int(g2b_hour)
    g2b_hour += -1
    if g2b_hour < 0:
        g2b_hour += 24
    g2b_hour = str(g2b_hour)
if 0 <= int(g2b_minute) < 10:
    g2b_minute = list(str(g2b_minute))
    g2b_minute.insert(0,"0")
    g2b_minute = "".join(g2b_minute)

print(str(g2b_hour)+":"+str(g2b_minute))
 		 	     				   	 					 	  			