def get_min_units(sell_order, buy_order):
    """
    Get the minimum units between orders
    :param sell_order: sell order
    :param buy_order: buy order
    :return: minimum units between orders
    """
    sell_units = sell_order['volume_remain']
    buy_units = buy_order['volume_remain']
    return min(sell_units, buy_units)