Years may wrinkle the skin, but to give up enthusiasm wrinkles the soul.
歲月留痕，只及肌膚；激情不再，皺起心靈。———— Samuel Ullman
收藏下這些小程序，以后可能會(huì)用到~經(jīng)網(wǎng)友 Rming 的指正，由之前的ceil函數(shù)修改為floor函數(shù)。~