由是先主遂诣亮，凡三往，乃见。因屏人曰：“汉室倾颓，奸臣窃命，主上蒙尘。孤不度德量力，欲信大义于天下，而智术浅短，遂用猖獗，至于今日。然志犹未已，君谓计将安出？”

亮答曰：“自董卓已来，豪杰并起，跨州连郡者不可胜数。曹操比于袁绍，则名微而众寡，然操遂能克绍，以弱为强者，非惟天时，抑亦人谋也。今操已拥百万之众，挟天子而令诸侯，此诚不可与争锋。孙权据有江东，已历三世，国险而民附，贤能为之用，此可以为援而不可图也。荆州北据汉、沔，利尽南海，东连吴会，西通巴、蜀，此用武之国，而其主不能守，此殆天所以资将军，将军岂有意乎？益州险塞，沃野千里，天府之土，高祖因之以成帝业。刘璋暗弱，张鲁在北，民殷国富而不知存恤，智能之士思得明君。将军既帝室之胄，信义著于四海，总揽英雄，思贤如渴，若跨有荆、益，保其岩阻，西和诸戎，南抚夷越，外结好孙权，内修政理；天下有变，则命一上将将荆州之军以向宛、洛，将军身率益州之众出于秦川，百姓孰敢不箪食壶浆以迎将军者乎？诚如是，则霸业可成，汉室可兴矣。”
先主曰：“善！”于是与亮情好日密。

关羽、张飞等不悦，先主解之曰：“孤之有孔明，犹鱼之有水也。愿诸君勿复言。”羽、飞乃止。

阅读理解

    Perhaps you think you could easily add to your happiness with more money. Strange as it may seem, if you're unsatisfied, the issue is not a lack of means to meet your desires but a lack of desires—not that you cannot satisfy your tastes but that you don't have enough tastes.

    Real riches consist of well-developed and hearty capacities (能力) to enjoy life. Most people are already swamped (淹没) with things. They eat, wear, go and talk too much. They live in too big a house with too many rooms, yet their house of life is a hut（草棚）.Your house of life ought to be a mansion (豪宅), a royal palace. Every new taste, every additional interest, every fresh enthusiasm adds a room. Here are several rooms your house of life should have.

    Art should be a desire for you to develop simply because the world is full of beautiful things. If you only understood how to enjoy them and feed your spirit on them, they would make you as happy as to find plenty of ham and eggs when you're hungry.

    Literature, classic literature, is a beautiful, richly furnished room where you might find many an hour of rest and refreshment. To gain that love would go toward making you a rich person, for a rich person is not someone who has a library but who likes a library.

    Music like Mozart's and Bach's shouldn't be absent. Real riches are of the spirit. And when you've brought that spirit up to where classical music feeds it and makes you a little drunk, you have increased your thrills(excitement) and bettered them. And life is a matter of thrills.

    Sports, without which you remain poor, mean a lot in life. No matter who you are, you would be more human, and your house of life would be better supported against the bad days, if you could, and did, play a bit.

    Whatever rooms you might add to your house of life, the secret of enjoying life is to keep adding.

已知x,y满足线性约束条件$\left\{\begin{array}{c}\begin{array}{c}x-y+1\ge 0\\ x+y-2\le 0\\ x+4y+1\ge 0\end{array}\\ \end{array}\right.$，若$\overrightarrow{a}=\left(x,-2\right)$，$\overrightarrow{b}=\left(1,y\right)$，则$z=$$\overrightarrow{a}·\overrightarrow{b}$的最大值是（   ）