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.
def main_function():
    current_time = [int(i) for i in input().split(":")]
    slept_time = [int(i) for i in input().split(":")]
    if current_time[1] >= slept_time[1]:
        minutes = current_time[1] - slept_time[1]
    else:
        if not current_time[0] == 0:
            current_time[0] -= 1
        else:
            current_time[0] == 23
        minutes = 60 + current_time[1] - slept_time[1]
    if current_time[0] >= slept_time[0]:
        hour = current_time[0] - slept_time[0]
    else:
        hour = 24 + current_time[0] - slept_time[0]
    if len(str(hour)) == 1:
        hor = "0" + str(hour)
    else:
        hor = str(hour)
    if len(str(minutes)) == 1:
        minu = "0" + str(minutes)
    else:
        minu = str(minutes)
    return hor + ":" + minu










print(main_function())