{"code":"insul","name":"Cách nhiệt","description":"Cho một dãy $N$ viên gạch lần lượt có độ cách nhiệt là các số $a_1 ... a_N$. Nếu xếp lần lượt các viên gạch theo trình tự đó thì độ cách nhiệt cả khối là $a_1+a_2+⋯+a_N+max(0,a_2−a_1)+max(0,a_3−a_2)+⋯+max(0,a_N−a_{N−1})$. Nhiệm vụ của bạn là tìm cách xếp sao cho độ cách nhiệt của cả khối là lớn nhất có thể.\r\n\r\n#### Input\r\n- Dòng đầu ghi số nguyên dương $N$ ($0< n≤ 10^5$).\r\n- $N$ dòng sau mỗi dòng ghi một số $a_i$ ($1≤ i≤ N$ và $1≤ a_i≤ 10000$).\r\n\r\n#### Output\r\n- Ghi trên một dòng kết quả cần tìm.\r\n#### Example\r\n!!! question \"Test 1\"\r\n    ???+ \"Input\"\r\n        ```sample\r\n        4\r\n        5\r\n        4\r\n        1\r\n        7 \r\n        ```\r\n    ???+ success \"Output\"\r\n        ```sample\r\n        24\r\n        ```","points":300.0,"partial":true,"time_limit":1.0,"memory_limit":262144,"short_circuit":false,"allowed_languages":[3,4,34,36,37,5,6,11,12,14,28,2,38,39,9,18,17,29,23,27,35,25,26,10,7,19,32,1,8,15,16,24,20,33,13,41,21,40],"is_public":true,"is_manually_managed":false,"permissions":{"can_edit":false}}