诗歌鉴赏

                                                                                                                春望
                                                                                                 国破山河在，城春草木深。
                                                                                                 感时花溅泪，恨别鸟惊心。
                                                                                                 烽火连三月，家书抵万金。
                                                                                                 白头搔更短，浑欲不胜簪。

已知P是椭圆$\frac{x^2}{100}+\frac{y^2}{36}=1$上的一点，若P到椭圆右准线的距离是$\frac{17}{2}$，则点P到左焦点的距离是        （   ）

（从上到下依次填写）