perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance defined perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance perseverance