{"raw_statement":[{"iden":"problem statement","content":"There are $N$ boxes arranged in a row. Initially, the $i$\\-th box from the left contains $a_i$ candies.\nSnuke can perform the following operation any number of times:\n\n*   Choose a box containing at least one candy, and eat one of the candies in the chosen box.\n\nHis objective is as follows:\n\n*   Any two neighboring boxes contain at most $x$ candies in total.\n\nFind the minimum number of operations required to achieve the objective."},{"iden":"constraints","content":"*   $2 ≤ N ≤ 10^5$\n*   $0 ≤ a_i ≤ 10^9$\n*   $0 ≤ x ≤ 10^9$"},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$N$ $x$\n$a_1$ $a_2$ $...$ $a_N$"},{"iden":"sample input 1","content":"3 3\n2 2 2"},{"iden":"sample output 1","content":"1\n\nEat one candy in the second box. Then, the number of candies in each box becomes $(2, 1, 2)$."},{"iden":"sample input 2","content":"6 1\n1 6 1 2 0 4"},{"iden":"sample output 2","content":"11\n\nFor example, eat six candies in the second box, two in the fourth box, and three in the sixth box. Then, the number of candies in each box becomes $(1, 0, 1, 0, 0, 1)$."},{"iden":"sample input 3","content":"5 9\n3 1 4 1 5"},{"iden":"sample output 3","content":"0\n\nThe objective is already achieved without performing operations."},{"iden":"sample input 4","content":"2 0\n5 5"},{"iden":"sample output 4","content":"10\n\nAll the candies need to be eaten."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}