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.
wo_time = input().split(":")
du_time = input().split(":")
sl_time_h = int(wo_time[0]) - int(du_time[0])
sl_time_m = int(wo_time[1]) - int(du_time[1])
if(sl_time_h < 0):
    sl_time_h = (24 + sl_time_h)
if(sl_time_m < 0):
    sl_time_m = (60 + sl_time_m)

if(sl_time_h < 10):
    sl_time_h_string = '0' + str(sl_time_h)
else:
    sl_time_h_string = str(sl_time_h)

if(sl_time_m < 10):
    sl_time_m_string = '0' + str(sl_time_m)
else:
    sl_time_m_string = str(sl_time_m)

print(str(sl_time_h_string) + ':' + str(sl_time_m_string))
