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.
# -*- coding: utf-8 -*-
"""
Created on Wed Jan 11 12:10:04 2023

@author: Lenovo
"""

sh,sm = tuple(map(int,input().split(':')))
th,tm = tuple(map(int,input().split(':')))

h,m=0,0

if tm>sm:
    m = sm-tm+60
    h = -1
else:
    m = sm-tm

h += sh - th

if h<0:
    h=24+h

h = str(h)
m = str(m)

if len(h)==1:
    h = '0'+h
if len(m)==1:
    m = '0'+m
print(f'{h}:{m}')
