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 math import floor
s = input().split(':')
t = input().split(':')

s = int(s[0])*60 + int(s[1])
t = int(t[0])*60 + int(t[1])

w = s-t

if w < 0:
    w = 24*60 + w

h = ''
m = ''

if floor(w/60) < 10:
    h = '0'+str(floor(w/60))
else:
    h = str(floor(w/60))

if w%60 < 10:
    m = '0'+str(w%60)
else:
    m = str(w%60)

print(h+':'+m)

 		   	 	  	  		 	 			 	   			