阅读下面一首诗，回答问题。
                                                                                                                 相见欢
                                                                                                                      李煜
                                                                                无言独上西楼，月如钩。寂寞梧桐深院锁清秋。
                                                                                剪不断，理还乱，是离愁。别是一般滋味在心头。