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.
s = input()
t = input()
hour1 = int(s[0])*10 + int(s[1])
min1 = int(s[3])*10 + int(s[4])
hour2 = int(t[0])*10 + int(t[1])
min2 = int(t[3])*10 + int(t[4])
if min1 < min2:
    min3 = min1 + 60 -min2
    if hour1 == 0:
        hour1 = 23
    else:
        hour1 -= 1
else:
    min3 = min1 - min2
if hour1 < hour2:
    hour3 = hour1 + 24 -hour2
else:
    hour3 = hour1 - hour2
if hour3 < 9:
    print('0'+str(hour3)+':',end='')
else:
    print(str(hour3) + ':', end='')
if min3 < 9:
    print('0'+str(min3))
else:
    print(str(min3))