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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _mark_candidate_indexes(lines, candidate):
 """Mark candidate indexes with markers Markers: * c - line that could be a signature line * l - long line * d - line that starts with dashes but has other chars as well 'cdc' """

    # at first consider everything to be potential signature lines
    markers = list('c' * len(candidate))

    # mark lines starting from bottom up
    for i, line_idx in reversed(list(enumerate(candidate))):
        if len(lines[line_idx].strip()) > TOO_LONG_SIGNATURE_LINE:
            markers[i] = 'l'
        else:
            line = lines[line_idx].strip()
            if line.startswith('-') and line.strip("-"):
                markers[i] = 'd'

    return "".join(markers)