Introduction - If you have any usage issues, please Google them yourself
Geographers often measurement and analysis of some rivers. They began in the downstream direction equidistant chose n upstream (<= 30,000) a shop measuring water depth. Get a set of data d1, d2, d3 ...... .dn, back in the lab after data analyst data needs to be analyzed according to discover hidden behind the data rule. Recently, Dr. Oolong find some related hydrological phenomena and bed topography, so he instructed the analyst to find some ups and downs of the largest rivers in the difference does not exceed k (<= 100) for the longest period. This may seem like a complicated question, because the task is urgent, analysts to turn to you, and tell you all the data are accurate to Dr. everybody.