def name_to_id(s):
    """Generate block identifier from url string

    Example input:

    al/2013/100cm/rgb/30085/m_3008501_ne_16_1_20130928.tif
    """
    # cell: 30085
    # stem: m_3008501_ne_16_1_20130928.tif
    cell, stem = s.split('/')[4:]

    # Keep text before date
    # m_3008501_ne_16_1_
    stem = stem[:18]

    # Concatenate
    return f'{cell}/{stem}'