from pandas import DataFrame, Series

def signals(data: DataFrame) -> Series:
    """
    Generate swing trading signals based on the High Volume Days strategy.

    Returns a Series with 'L' for long signals and 'N' otherwise.
    """
    data['200_MA'] = data['Close'].rolling(window = 200).mean()
    above_200_ma = data['Close'] > data['200_MA']

    highest_volume = data['Total Volume'] == data['Total Volume'].rolling(window = 5).max()
    close_lower_than_open = data['Close'] < data['Open']

    signal_condition = above_200_ma & highest_volume & close_lower_than_open
    signals = signal_condition.apply(lambda condition: 'L' if condition else 'N')
    return signals