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()
s = s.split(":")
t = input()
t = t.split(":")
if (int(s[1]) - int(t[1]) < 0):
    temp2 = 60 - abs(int(s[1]) - int(t[1]))
    tmp = int(t[0])
    tmp += 1
    t[0] = tmp
else:
    temp2 = abs(int(s[1]) - int(t[1]))
if (int(s[0]) - int(t[0]) < 0):
    temp1 = 24 - abs(int(s[0]) - int(t[0]))
else:
    temp1 = abs(int(s[0]) - int(t[0]))
    
if (len(str(temp1)) == 1 and len(str(temp2)) == 1):
    print("0" + str(temp1) + ":" + "0" + str(temp2))
elif (len(str(temp1)) == 2 and len(str(temp2)) == 1):
    print(str(temp1) + ":" + "0" + str(temp2))
else:
    print(str(temp1) + ":" + str(temp2))