def complete_sulci_name(sulci_list, side):
    """Function gathering sulci and side to obtain full name of sulci

    It reads suli prefixes from a list and adds a suffix depending on a given
    side.

    Args:
        sulci_list: a list of sulci
        side: a string corresponding to the hemisphere, whether 'L' or 'R'

    Returns:
        full_sulci_list: a list with full sulci names, ie with side included
    """
    if any("right" in s for s in sulci_list) or any("left" in s for s in sulci_list):
        return sulci_list
    else:
        side = 'right' if side=='R' else 'left'
        suffix = '_' + side
        if isinstance(sulci_list, list):
            full_sulci_list = []
            for sulcus in sulci_list:
                sulcus += suffix
                full_sulci_list.append(sulcus)
            return full_sulci_list
        else:
            return sulci_list + suffix