def sanitize_cloud(cloud: str) ->str:
    """
    Fix rare cloud layer issues
    """
    if len(cloud) < 4:
        return cloud
    if not cloud[3].isdigit() and cloud[3] not in ('/', '-'):
        if cloud[3] == 'O':
            cloud = cloud[:3] + '0' + cloud[4:]
        elif cloud[3] != 'U':
            cloud = cloud[:3] + cloud[4:] + cloud[3]
    return cloud
