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()
l3=[]
l4=[]
l1 = s.split(":")
l2 = t.split(":")

if l1[0]=="00" and l2[0]!="00":
                       l3.append(24-int(l2[0]))
else:                       
                       l3.append(int(l1[0])-int(l2[0]))
l3.append(int(l1[1])-int(l2[1]))
s1=""
s2=""
if l3[0]<10:
                       s1=s1+"0";
                       s1=s1+str(l3[0])
else:
                       s1=s1+str(l3[0])
if l3[1]<10:
                       s2=s2+"0";
                       s2=s2+str(l3[1])
else:
                       s2=s2+str(l3[1])


s3=""
s3=s3+s1
s3=s3+":"
s3=s3+s2
print(s3)



