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.
jawab=[0,0]
a=input().split(":")
b=input().split(":")
if int(a[1])<int(b[1]):
    if a[0]!="00":
        a[0]=int(a[0])-1
    else:
        a[0]=23
    a[1] = int(a[1])+60
    jawab[1]= str(a[1] - int(b[1]))
else:
    jawab[1]= str(int(a[1]) - int(b[1]))

if int(a[0])<int(b[0]):
    if a[0]=="00":
        a[0]=23
        b[0]=int(b[0])-1
    else:
        b[0]= int(b[0])-int(a[0])-1
        a[0]=23
    jawab[0]=str(a[0]-b[0])
else:
    jawab[0]=str(int(a[0]) - int(b[0]))

if len(jawab[0])==1:
    jawab[0]="0"+str(jawab[0])
if len(jawab[1])==1:
    jawab[1]="0"+str(jawab[1])

print(":".join(jawab))

			 	    	 		  		 		 	     	 	