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.
import os

time=input()
spend=input()
var=0
m=0
h=0
if int(time[3:])-int(spend[3:])<0:
	m=str(60+int(time[3:])-int(spend[3:]))
	var=1
else:
	m=str(int(time[3:])-int(spend[3:]))
if int(time[0:2])-int(spend[0:2])<0:
	h=str(24+int(time[0:2])-int(spend[0:2])-var)
else:
	h=str(int(time[0:2])-int(spend[0:2])-var)
if len(h)==1:
	h="0"+h
if len(m)==1:
	m="0"+m
print(h,end='')
print(":",end='')
print(m)
