def get_max_size(pool, num_option, item_length):
max_items = POOL_SIZE / item_length<EOL>existing = POOL_OPTION_MIN_SIZE * num_option + sum([max(<NUM_LIT:0>, len(pool.get(i, {})) - <NUM_LIT:5>) for i in xrange(num_option)])<EOL>return int(max_items - existing)<EOL>
Calculate the max number of item that an option can stored in the pool at give time.

This is to limit the pool size to POOL_SIZE

Args:
    option_index (int): the index of the option to calculate the size for
    pool (dict): answer pool
    num_option (int): total number of options available for the question
    item_length (int): the length of the item

Returns:
    int: the max number of items that `option_index` can have