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.
sa,ta=input().split(":"),input().split(":")
list1=[0,0,0,0]
s,t=[],[]
for i in range(len(sa)):
    for j in sa[i]:
        s.append(int(j))
for i in range(len(ta)):
    for j in ta[i]:
        t.append(int(j))
if 0<=int(sa[0])<=23 and 0<=int(ta[0])<=23 and 0<=int(sa[1])<=59 and 0<=int(ta[1])<=59:
    if int(sa[1])>=int(ta[1]):
        a=str(int(sa[1])-int(ta[1]))
        if int(a)>9:
            list1[2],list1[3]=int(a[0]),int(a[1])
        else:
            list1[2],list1[3]=0,int(a[0])
    else:
        a=int(ta[0])+1
        ta[0]=str(a)
        if s[3]>=t[3]:
            list1[3]=s[3]-t[3]
        else:
            list1[3]=(10+s[3])-t[3]
            t[2]+=1
        if s[2]>=t[2]:
            list1[2]=s[2]-t[2]
        else:
            list1[2]=(6+s[2])-t[2]
            t[1]+=1
    if int(sa[0])>=int(ta[0]):
        a=str(int(sa[0])-int(ta[0]))
        if int(a)>9:
            list1[0],list1[1]=int(a[0]),int(a[1])
        else:
            list1[0],list1[1]=0,int(a[0])
    else:
        if s[1]>=t[1]:
            list1[1]=s[1]-t[1]
        else:
            list1[1]=(4+s[1])-t[1]
            t[0]+=1
        if s[0]>=t[0]:
            list1[0]=s[0]-t[0]
        else:
            list1[0]=(3+s[0])-t[0]
            t[0]+=1    