def extract_frags(gem_list):
    """
    Extract necessary information from input gem.
    Args:
       gem_list (list): list with 10 items as encoded in PlinePgem file
    Returns:
       frags (list of list): [chrom,start,end] for each fragment 
    """
    raw_frags = gem_list[4].split(";")
    frags = []
    for j in range(len(raw_frags)):
        bedentry = raw_frags[j].split("(")[0].replace("-", ":").split(":")
        bedentry[1] = int(bedentry[1])
        bedentry[2] = int(bedentry[2])
        frags.append(bedentry)
    return frags