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()
h = 0
minu = 0 
l = s.split(':')
m = t.split(':')
hs = int(l[0])
ms = int(l[1])
th = int(m[0])
ts = int(m[1])
if hs== 0: 
	hs=24
	h =hs-th
	minu = ms-ts
	if h==24:
			h=0
	if h<10 and minu<10 :
		#print("inside")
		
		h=str(h)
		minu=str(minu)
		print("0"+h+":"+"0"+minu)
	elif h>=10 and minu<10:
		#print("outside")
		if h==24:
			h=0
		h=str(h)
		minu=str(minu)
		print(h+":"+"0"+minu)
else:
	h=hs-th
	minu = ms-ts
	if h==24:
			h=0
	if h<10 and minu<10 :
		#print("inside")
		
		h=str(h)
		minu=str(minu)
		print("0"+h+":"+"0"+minu)
	elif h>=10 and minu<10:
		#print("outside")
		if h==24:
			h=0
		h=str(h)
		minu=str(minu)
		print(h+":"+"0"+minu)

