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.
time1 = list(map(int, input().split(':')))
time2 = list(map(int, input().split(':')))
output = []
if time1[1] - time2[1] < 0:
    output.append(time1[1] - time2[1]+60)
    time1[0] -= 1
else:
    output.append(time1[1] - time2[1])

if time1[0] - time2[0] < 0:
     output.append(time1[0] - time2[0]+24)
else:
    output.append(time1[0] - time2[0])

if int(output[0])<10:
    output[0] = '0' + str(output[0])

if int(output[1]) < 10:
    output[1] = '0' + str(output[1])

print(str(output[1]) + ':' + str(output[0]))