The cows are trying to become better athletes, so Bessie is running on a track for exactlyN(1 ≤N≤ 10,000) minutes. During each minute, she can choose to either run or rest for the whole minute.
The ultimate distance Bessie runs, though, depends on her ‘exhaustion factor’, which starts at 0. When she chooses to run in minutei, she will run exactly a distance ofDi(1 ≤Di≤ 1,000) and her exhaustion factor will increase by 1 — but must never be allowed to exceedM(1 ≤M≤ 500). If she chooses to rest, her exhaustion factor will decrease by 1 for each minute she rests. She cannot commence running again until her exhaustion factor reaches 0. At that point, she can choose to run or rest.
At the end of theNminute workout, Bessie’s exaustion factor must be exactly 0, or she will not have enough energy left for the rest of the day.
Find the maximal distance Bessie can run.
，想想我的影子，我会在你身后给你一个拥抱;
