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(":")
res1 = int(l1[0])-int(l2[0])
res2 = int(l1[1])-int(l2[1])

if res2<0:
                       res2=res2+60
                       res1=res1-1
elif res1<0:
                       res1=res1+24
s1=""
if res1<10 and res2<10:
                       
                       s1=s1+"0"+str(res1)
                       s1=s1+":"

                       s1=s1+"0"+str(res2)
if res1<10 and res2>10:
                       
                       s1=s1+"0"+str(res1)
                       s1=s1+":"

                       s1=s1+str(res2)
                       
if res1>10 and res2<10:
                       
                       s1=s1+str(res1)
                       s1=s1+":"

                       s1=s1+"0"+str(res2)
                       
else:
                       
                       s1=s1+str(res1)
                       s1=s1+":"

                       s1=s1+str(res2)


print(s1)

