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.
from datetime import datetime
s = input()
t = input()
t1 = datetime.strptime(s,"%H:%M")
t2 = datetime.strptime(t,"%H:%M")

m_diff = t1.minute - t2.minute
h_diff = h_diff = t1.hour - t2.hour
if m_diff >= 0:
	if h_diff < 0:
		h_diff = 24 + h_diff
elif m_diff < 0:
	m_diff = 60 + m_diff
	h_diff -=1
	if h_diff < 0:
		h_diff = 24 + h_diff	

#print (h_diff,m_diff)

"""s = ""
if h_diff < 10:
	s = "0"+str(h_diff)
else:
	s = str(h_diff)	

print (s)
"""

if h_diff < 10:
	s = "0"+str(h_diff)
	if m_diff < 10:
		s = s +":" + "0"+str(m_diff)
	else:
		s = s + ":" +str(m_diff)
else:
	s = str(h_diff)	
	if m_diff < 10:
		s = s + ":"+"0"+str(m_diff)
	else:
		s = s +":"+ str(m_diff)

print(s)
