"""

python timeinterval 8:20 10:30


"""

def zeit_in_minute(zeit: str) -> int:
    (h,m) = zeit.split(":")
    h = int(h)
    m = h*60 + (int(m))
    return m


def zeit_differenz(start, end):
    return abs(start - end)



if __name__ == "__main__":
    # eingabe entgegen nehmen
    start_zeit = input("startzeit")
    ende_zeit = input("endzeit")
    start_minuten = zeit_in_minute(start_zeit)
    end_minute = zeit_in_minute(ende_zeit)
    diff = zeit_differenz(start_minuten, end_minute)
    print(diff)