def chunks(n, l):
    for i in xrange(0, len(l), n):
        yield l[i:i+n]

DAYS_PER_MONTH = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ]
def date_to_days(date):
    splitted = date.split('/')
    return sum(DAYS_PER_MONTH[1:int(splitted[0])]) + int(splitted[1])

def max_occupancy(fpath):
    guests = map(
        lambda x: ( x[0], date_to_days(x[1]), date_to_days(x[2]) ),
        chunks(3,
            open(fpath).read().split()
        )
    )

    current_guests = []
    max_current = 0
    for entry in guests:
        current_guests = filter(lambda x: x >= entry[2], current_guests) + [ entry[2] ]
        if len(current_guests) > max_current:
            max_current = len(current_guests)
    return max_current

print(max_occupancy("text.txt"))