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.
hs,ms = map(int,input().split(":"))
ht,mt = map(int,input().split(":"))

if ht <= hs:
    hs-=ht
    if mt <= ms:
        ms-=mt
    elif hs > 0:
        hs-=1
        x = 60 - mt
        if x + ms < 60:
            ms+=x
        else:
            hs+=1
            ms = (ms+x)-60
    elif hs == 0:
        hs = 23
        x = 60 - mt
        if x + ms < 60:
            ms+=x
        else:
            hs = 00
            ms = (ms+x)-60
elif ht > hs:
    hs = 24 - (ht-hs)
    if mt <= ms:
        ms-=mt
    elif hs > 0:
        hs-=1
        x = 60 - mt
        if x + ms < 60:
            ms+=x
        else:
            hs+=1
            ms = (ms+x)-60
    elif hs == 0:
        hs = 23
        x = 60 - mt
        if x + ms < 60:
            ms+=x
        else:
            hs = 00
            ms = (ms+x)-60
if hs < 10 and ms < 10:
    print(f"0{hs}:0{ms}")
elif hs >= 10 and ms < 10:
    print(f"{hs}:0{ms}")
elif hs < 10 and ms >= 10:
    print(f"0{hs}:{ms}")
else: print(f"{hs}:{ms}")