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.
# LUOGU_RID: 92912857
s = input()
t = input()
s1 = int(s[0:2])*60+int(s[3:5])
t1 = int(t[0:2])*60+int(t[3:5])
s1 = s1 - t1
if s1<0: 
    s1 = s1+24*60
s11 = s1//60
s22 = s1 % 60
if s11//10 == 0:
    print('0'+str(s11)+":",end='')
else:
    print(str(s11)+":",end='')
if s22//10 == 0:
    print('0'+str(s22),end='')
else:
    print(str(s22),end='')