def get_compatible_vep_version(vep_cache_version, ftp_source):
    """
    Gets VEP version compatible with given cache version, according to which FTP source the cache comes from.
    If source is Ensembl Genomes the version should be vep_cache_version + 53, otherwise the versions are equal.
    """
    return vep_cache_version + 53 if ftp_source == 'genomes' else vep_cache_version