def parse_markers(f):
    """
    Parse markers from mrk file f. Each marker determines a time point
    and an according class-label of the movement that was imagined.

    Args:
        f (String) - an mrk file

    Returns:
        tuple of lists of ints - one list for the markers, one for 
                                 the labels
    """
    mrks = list()
    y = list()
    with open(f) as f_m:
        for line in f_m:
            mrk, cls = line.strip('\n').split('\t')
            mrks.append(int(float(mrk)))
            y.append(int(float(cls)))
    return mrks, y